Corporate Tax Filing Singapore: Complete Guide for SMEs [2025]

Every Singapore company must file a corporate tax return with IRAS annually, regardless of whether you made a profit or loss. If you're new to Singapore's tax system or simply want to ensure you're doing everything correctly, this guide explains everything you need to know about corporate tax filing.

Corporate tax filing involves submitting a tax return (Form C, C-S, or C-S Lite) to the Inland Revenue Authority of Singapore (IRAS) that details your company's income, expenses, and taxable profit for the financial year. The process requires proper accounting records, financial statements, and an understanding of what expenses are tax-deductible.

Many business owners find tax filing overwhelming, especially when dealing with terms like "Year of Assessment," "chargeable income," and different form types. This guide breaks down the entire process into clear, actionable steps.

Understanding Singapore Corporate Tax
Types of Tax Forms
Corporate Tax Filing Deadlines
What You Need to File
Common Tax Deductions for SMEs
Step-by-Step Filing Process
Common Mistakes to Avoid
DIY vs Hiring a Tax Agent
Frequently Asked Questions

In this guide, you will learn:

How Singapore's corporate tax system works and key deadlines
The difference between Form C, Form C-S, and Form C-S Lite
What expenses you can and cannot deduct to minimize your tax bill
Step-by-step instructions for filing your tax return
Common mistakes that trigger IRAS audits and how to avoid them
When to DIY your tax filing versus hiring a professional

Whether you're filing for the first time or want to ensure you're claiming all available deductions, this guide provides everything you need for accurate, compliant tax filing.

Understanding Singapore Corporate Tax

Singapore operates a territorial tax system with one of the most competitive corporate tax rates globally. Understanding the basics and historical context will help you navigate the filing process with confidence.

Singapore's Corporate Tax Rate in Regional Context

The standard corporate tax rate in Singapore is 17% on chargeable income, significantly lower than many comparable economies:

Regional Comparison:

Singapore: 17%
Malaysia: 24%
Thailand: 20%
Indonesia: 22%
Philippines: 25%
Australia: 30%
Hong Kong: 16.5%
United Kingdom: 25%

Singapore's low rate is deliberate policy, not historical accident. When Singapore gained independence in 1965, the government adopted a tax system inherited from British colonial administration. The Economic Development Board (EDB) was established to attract foreign investment, and competitive corporate taxation became a cornerstone of this strategy.

The corporate tax rate has been progressively reduced from 40% in the 1960s to the current 17% (set in 2010). This reduction was part of Singapore's transformation into a regional business hub, competing directly with Hong Kong and attracting multinational corporations to establish regional headquarters.

Corporate Tax Rate and Exemptions

Most SMEs pay significantly less than 17% due to various exemptions:

Startup Tax Exemption (SUTE): Qualifying new companies enjoy exemptions for their first three Years of Assessment:

First $100,000 of chargeable income: 75% exempt (effective rate: 4.25%)
Next $100,000 of chargeable income: 50% exempt (effective rate: 8.5%)

Partial Tax Exemption (PTE): All other companies benefit from:

First $10,000 of chargeable income: 75% exempt
Next $190,000 of chargeable income: 50% exempt

Example: A company with $200,000 chargeable income pays approximately $26,350 in tax instead of $34,000 at full rate, saving $7,650 annually.

Year of Assessment (YA)

Your Year of Assessment is the year following your Financial Year End (FYE). This determines your filing deadline.

Example: FYE 31 December 2024 → YA 2025 → File by 30 November 2025

Chargeable Income

Corporate tax applies to chargeable income, not revenue. The calculation is complex and involves numerous adjustments. We'll cover the detailed tax computation methodology in Section 6 (Step-by-Step Filing Process).

Basic concept: Revenue minus allowable expenses and adjustments equals chargeable income. The actual computation involves capital allowances, non-deductible expenses, and various IRAS-specific adjustments that require careful attention.

Tax Residency: Detailed Determination

Tax residency affects exemptions and Double Tax Agreement (DTA) benefits. Determination can be complex.

A company is tax resident in Singapore if:

Criterion 1: Incorporation

Incorporated in Singapore under the Companies Act, OR

Criterion 2: Management and Control

The company's management and control are exercised in Singapore

What "Management and Control" Means:

IRAS considers where strategic decisions are made, not merely where routine operations occur. Key factors:

Where board meetings are held (where directors physically meet to make decisions)
Where directors reside (if majority are Singapore residents, likely Singapore control)
Where key business decisions are made (strategic planning, major contracts, financing decisions)

Scenario 1: Clear Singapore Tax Resident

Company incorporated in Singapore
All directors are Singapore residents
Board meetings held in Singapore
Day-to-day operations in Singapore
Result: Singapore tax resident

Scenario 2: Foreign-Incorporated Company (May Be Singapore Resident)

Company incorporated in Hong Kong
Two directors: one in Hong Kong, one in Singapore
Key strategic decisions made by Singapore director
Board meetings held in Singapore
Result: Likely Singapore tax resident despite foreign incorporation

Scenario 3: Singapore Company But Foreign Tax Resident

Company incorporated in Singapore
All directors reside in Malaysia
Board meetings held in Malaysia
Strategic decisions made in Malaysia
Only administrative work in Singapore
Result: May be considered Malaysian tax resident (dual residency, resolved by DTA tie-breaker rules)

Why Residency Matters:

Tax resident companies access SUTE and PTE exemptions
Access to Singapore's 90+ DTAs to avoid double taxation
Withholding tax implications for payments to non-residents
Filing obligations differ

Dual Residency: If a company could be resident in two countries, the relevant DTA typically uses a "tie-breaker" test based on "place of effective management." This usually means where the highest-level decisions are made.

If you're unsure about your company's tax residency status, particularly with foreign directors or cross-border operations, consult IRAS or a tax professional. Incorrect residency determination can result in loss of exemptions or unexpected tax obligations in multiple jurisdictions.

Types of Tax Forms

Singapore companies file one of three tax forms depending on their revenue and what claims they're making. Choosing the correct form is essential for smooth processing.

Understanding the Three Tax Forms

Form C-S (Lite) - Simplest option

Your company qualifies if it meets all these conditions:

Incorporated in Singapore
Annual revenue ≤ $200,000
Only income taxed at 17%
Not claiming:
- Carry-back of current year capital allowances/losses
- Group relief
- Investment allowance
- Foreign tax credit or tax deducted at source

Form C-S - Standard option for most SMEs

Your company qualifies if it meets all these conditions:

Incorporated in Singapore
Annual revenue ≤ $5 million
Only income taxed at 17%
Not claiming:
- Carry-back of current year capital allowances/losses
- Group relief
- Investment allowance
- Foreign tax credit or tax deducted at source

Form C - Detailed option

You must file Form C if:

Annual revenue exceeds $5 million, OR
You're claiming any of the four items listed above (group relief, foreign tax credit, etc.), OR
Your company has income taxed at rates other than 17%

Key Differences: What Information Each Form Requires

The main difference between forms isn't just revenue threshold—it's how much financial detail you need to provide.

Comparison of Information Required:

Information Category	Form C-S (Lite)	Form C-S	Form C
Revenue threshold	≤ $200,000	≤ $5,000,000	> $5,000,000 or any revenue if claiming excluded items
Basic tax computation	✓ Required	✓ Required	✓ Required
Revenue figure	✓ Required	✓ Required	✓ Required
Gross profit/loss breakdown	✗ Not required	✓ Required	✓ Required
Directors' fees detail	✗ Not required	✓ Required	✓ Required
Staff remuneration detail	✗ Not required	✓ Required	✓ Required
Specific expense categories	✗ Not required	✓ Required	✓ Required
Balance sheet items	✗ Not required	✓ Required (e.g., trade receivables)	✓ Required (full details)
Capital allowances claims	✓ Can claim (but not carry back)	✓ Can claim (but not carry back)	✓ Can claim and carry back
Group relief	✗ Cannot claim	✗ Cannot claim	✓ Can claim
Foreign tax credit	✗ Cannot claim	✗ Cannot claim	✓ Can claim
Supporting schedules	Minimal	Moderate	Extensive

What this means practically:

Form C-S (Lite): You only need revenue figure and basic tax computation. Minimal financial statement detail required.
Form C-S: You need detailed profit and loss breakdown, directors' remuneration, employee costs, and selected balance sheet items.
Form C: You need comprehensive financial statements with full supporting schedules.

How to Determine Which Form to File

Step 1: Check your annual revenue

≤ $200,000 → potentially Form C-S (Lite)
$200,001 to $5,000,000 → potentially Form C-S
>$5,000,000 → must file Form C

Step 2: Check what you're claiming

Are you claiming any of these?

Group relief (transferring losses within group)
Foreign tax credit (tax paid overseas)
Carrying back current year losses/allowances to prior year
Investment allowance

If YES to any: You must file Form C regardless of revenue.

If NO to all: You can file C-S or C-S (Lite) based on revenue.

Step 3: Check income types

Income taxed at rates other than 17%? → must file Form C
Only income taxed at 17%? → Can use C-S if other conditions met

Real-World Examples

Example 1: Small retail shop

Revenue: $180,000
No group relief, no foreign income
Only standard capital allowance claims (not carrying back)
Qualifies for: Form C-S (Lite)
Information needed: Revenue, basic tax computation

Example 2: Consulting firm

Revenue: $450,000
Claiming capital allowances on equipment (but not carrying back to prior years)
No group relief or foreign tax credits
Qualifies for: Form C-S
Information needed: Revenue, gross profit, directors' fees, staff costs, selected expenses, trade receivables

Example 3: Company in group structure

Revenue: $800,000
Transferring losses to sister company (group relief)
Must file: Form C (group relief disqualifies from C-S)
Information needed: Full financial statements, group relief schedules

Example 4: Company with foreign operations

Revenue: $2 million
Claiming foreign tax credit for tax paid in Malaysia
Must file: Form C (foreign tax credit disqualifies from C-S)
Information needed: Full financial statements, foreign tax credit computation

Example 5: High-revenue company

Revenue: $8 million
No special claims
Must file: Form C (exceeds $5M threshold)
Information needed: Comprehensive financial statements

Common Confusion: Tax Form vs Audit Requirements

Important: Tax form requirements are different from audit exemption criteria.

For audit exemption, you need to meet 2 of these 3 criteria:

Annual revenue ≤ $10 million
Total assets ≤ $10 million
Employees ≤ 50

For Form C-S, you need:

Annual revenue ≤ $5 million
Not claiming the four excluded items
Only income taxed at 17%

This means:

You can file Form C-S but still need an audit (e.g., $4M revenue, $12M assets, 30 employees)
You can file Form C but be exempt from audit (e.g., $7M revenue, $8M assets, 40 employees)

They're separate requirements serving different purposes.

Estimated Chargeable Income (ECI)

Before filing your annual return, most companies must file an Estimated Chargeable Income (ECI) within three months of Financial Year End.

You're exempt from ECI if:

Annual revenue ≤ $5 million, AND
Estimated chargeable income is nil (zero)

What is ECI? An estimate of your taxable profit for the year submitted to help IRAS forecast tax collection.

Example: FYE 31 December 2024 → File ECI by 31 March 2025

Late filing penalty: $200 for initial delay, with escalating penalties for continued non-compliance.

The estimate doesn't need to be exact. If your actual chargeable income differs when filing the final return later, that's acceptable—IRAS understands estimates may change.

Can You Change Forms Year to Year?

Yes. The form you file depends on your circumstances each year.

Example scenarios:

Year 1: Revenue $150K, filed Form C-S (Lite)
Year 2: Revenue $3 million, file Form C-S (more revenue, need more detail)

Year 1: Revenue $800K, no group relief, filed Form C-S
Year 2: Revenue $900K, claiming group relief, file Form C (disqualified from C-S due to group relief claim)

The form selection is based on current year facts, not what you filed previously.

Summary: Quick Form Selection Guide

Your Situation	File This Form	Key Requirement
Revenue ≤ $200K, no special claims, simple structure	Form C-S (Lite)	Minimal financial detail
Revenue $200K-$5M, no special claims	Form C-S	Moderate financial detail required
Revenue > $5M	Form C	Full financial statements
Claiming group relief (any revenue level)	Form C	Group relief schedules
Claiming foreign tax credit (any revenue level)	Form C	Foreign tax credit computation
Carrying back losses/allowances (any revenue level)	Form C	Prior year reconciliation
Claiming investment allowance (any revenue level)	Form C	Investment allowance schedules
Income taxed at non-17% rates (any revenue level)	Form C	Tax rate reconciliation

When uncertain about which form to file or what information you need to prepare, our tax filing service can review your situation, determine the correct form, and handle the entire filing process.

Corporate Tax Filing Deadlines

Missing tax deadlines can result in penalties and complications with IRAS. Understanding Singapore's tax calendar helps you stay compliant and avoid unnecessary costs.

Key Deadline: 30 November

The most important date for corporate tax filing is 30 November of the year following your Financial Year End (FYE).

How it works:

Your Financial Year End determines your Year of Assessment (YA)
YA = FYE year + 1
Filing deadline = 30 November of the YA year

Examples:

Financial Year End	Year of Assessment	Filing Deadline
31 Dec 2024	YA 2025	30 Nov 2025
31 Mar 2024	YA 2025	30 Nov 2025
30 Jun 2024	YA 2025	30 Nov 2025
30 Sep 2024	YA 2025	30 Nov 2025

Notice that all companies with FYE in calendar year 2024 file by the same deadline: 30 November 2025.

Estimated Chargeable Income (ECI) Deadline

Most companies must file ECI within 3 months of their Financial Year End.

Exception: Companies with:

Annual revenue ≤ $5 million, AND
Estimated chargeable income is nil

Examples:

Financial Year End	ECI Deadline
31 Dec 2024	31 Mar 2025
31 Mar 2024	30 Jun 2024
30 Jun 2024	30 Sep 2024
30 Sep 2024	31 Dec 2024

Important: ECI deadline comes BEFORE the Form C/C-S filing deadline. Don't confuse the two.

Complete Tax Filing Timeline

Here's the full sequence of events for a typical company with FYE 31 December 2024:

31 December 2024 - Financial Year End

Close your books for the year
Begin preparing financial statements

By 31 March 2025 - ECI Deadline (3 months after FYE)

File Estimated Chargeable Income with IRAS
This is an estimate; adjustments are acceptable when filing final return

April to November 2025 - Preparation Period

Finalise financial statements
Prepare tax computation
Determine which form to file (C-S Lite, C-S, or C)
Gather supporting documents

By 30 November 2025 - Form C/C-S Filing Deadline

Submit Form C, C-S, or C-S (Lite) to IRAS
Include final tax computation
All companies with FYE in 2024 must file by this date

December 2025 onwards - Tax Assessment

IRAS reviews your filing
IRAS issues Notice of Assessment (NOA)
Tax payment due within 1 month of NOA

Penalties for Late Filing

Late ECI Filing:

Initial penalty: $200
Continued non-compliance: Additional penalties up to $1,000
Possible prosecution for persistent failure

Late Form C/C-S Filing:

First offence: $200 penalty
Repeated offences: Up to $1,000 penalty
Continued failure: Possible prosecution, with fines up to $5,000 and/or imprisonment

Late Payment of Tax:

5% penalty on unpaid tax immediately upon default
Additional 1% penalty for each month tax remains unpaid (capped at 12%)
Maximum total penalty: 17% of unpaid tax

Example: Tax due is $10,000. You pay 3 months late.

Initial 5% penalty: $500
Monthly 1% penalty × 3 months: $300
Total penalty: $800
Total amount due: $10,800

Extension of Filing Deadline

IRAS may grant extension in specific circumstances:

Automatic extension scenarios:

Companies filing through approved tax software (usually additional 30 days)
Tax agents filing multiple returns (may qualify for extended deadline)

Request for extension:

Must apply before original deadline
Valid reasons: complex restructuring, missing documents, overseas directors
IRAS reviews on case-by-case basis
No guarantee extension will be granted

How to request extension:

Submit request via myTax Portal
Provide clear explanation and supporting documents
Apply at least 2 weeks before deadline

Important: Extension request does not guarantee approval. Continue preparing your return as if no extension will be granted.

Payment Deadline

Tax payment is due within 1 month of the Notice of Assessment (NOA) date.

Timeline:

You file Form C/C-S by 30 November
IRAS reviews and issues NOA (typically 1-3 months later)
NOA states tax payable and payment deadline
Pay within 1 month of NOA date

Example:

Filed Form C-S: 15 November 2025
IRAS issued NOA: 20 January 2026
Payment deadline: 20 February 2026

Payment methods:

GIRO (recommended for monthly instalment plan)
Internet banking
AXS stations
SAM kiosks
Cheque

Monthly Instalment Plan (GIRO)

Instead of lump sum payment, you can pay tax in monthly instalments via GIRO.

How it works:

Spread payment over 12 months
Interest-free
Automatic deduction from your bank account

Eligibility:

Must set up GIRO arrangement with IRAS
Available for tax payable of any amount

Setup:

Apply via myTax Portal
Allow 1 month for GIRO arrangement to take effect
Set up BEFORE tax is due to avoid late payment penalties

What Happens If You Miss a Deadline?

Missed ECI deadline:

$200 penalty notice issued
File ECI immediately to avoid further penalties
Penalty must be paid separately from tax

Missed Form C/C-S deadline:

IRAS issues reminder
$200 penalty imposed
Further delays result in additional penalties
IRAS may issue estimated assessment (often higher than actual tax)
File immediately to avoid escalation

Missed payment deadline:

5% penalty added immediately
1% additional penalty each month
IRAS may take recovery action (debt collection, legal proceedings)
Pay immediately to stop penalties accumulating

If you realise you'll miss a deadline:

Don't ignore it
Contact IRAS immediately
Explain circumstances
Request extension or instalment arrangement
File/pay as soon as possible

Dormant Companies: Do Deadlines Apply?

Yes. ALL Singapore companies must file tax returns, including dormant companies.

Dormant company definition:

No business transactions during financial year
No income received

Filing requirement:

Must still file Form C-S or Form C-S (Lite)
Indicate "nil" for income and expenses
Same deadlines apply

Penalty for non-filing:

Same penalties apply even if company is dormant
Common misconception: "Dormant means no filing needed" - FALSE

Summary: Critical Dates to Remember

For companies with FYE 31 December 2024:

Date	Action Required
31 Dec 2024	Financial Year End
31 Mar 2025	File ECI (if required)
30 Nov 2025	File Form C/C-S/C-S (Lite)
Within 1 month of NOA	Pay corporate tax

General rules:

ECI: Within 3 months of FYE
Form C/C-S: By 30 November of YA year
Payment: Within 1 month of NOA

When deadlines fall on weekends or public holidays, the deadline extends to the next working day.

Staying ahead of these deadlines prevents penalties and ensures smooth compliance. If you find tax filing deadlines stressful or have missed past deadlines, our tax filing service handles all submissions on time, every time.

What You Need Before Filing

Proper preparation makes tax filing smoother and faster. Before you begin filing Form C, C-S, or C-S (Lite), gather these essential documents and information.

Financial Statements

All companies must prepare financial statements before filing tax returns, even if IRAS doesn't require you to submit them.

Required financial statements:

1. Profit and Loss Statement (Income Statement)

Revenue for the financial year
Cost of goods sold (if applicable)
Operating expenses by nature (not function). This can be found on the face of the P&L or in the notes
Net profit or loss before tax

2. Balance Sheet (Statement of Financial Position)

Assets (current and non-current)
Liabilities (current and non-current)
Equity

3. Notes to Financial Statements

Accounting policies
Breakdown of significant items
Related party transactions
Contingent liabilities

Financial reporting standards:

Financial statements should comply with Singapore Financial Reporting Standards (SFRS) or IFRS
Small companies may use simplified standards
Consistency in accounting policies year-over-year

Do you need to submit financial statements to IRAS?

No, not with your tax return unless you are filing Form C. However:

You must retain them for at least 5 years
IRAS may request them during review or audit
You need them to complete your tax computation

Tax Computation

Tax computation bridges your accounting profit to taxable profit. This is essential for all tax forms.

What tax computation includes:

Starting point:

Net profit/loss from financial statements

Add back:

Non-deductible expenses (entertainment, fines, capital expenditure, etc.)
Donations exceeding limits
Provisions not yet incurred
Personal expenses charged to company

Deduct:

Non-taxable income (tax-exempt dividends, capital gains)
Capital allowances
Approved donations (qualifying amounts)
Unutilised losses/allowances brought forward

Result:

Adjusted profit before capital allowances
Less current year capital allowances
Equals chargeable income

Example tax computation: Net profit per financial statements: $150,000
Add: Non-deductible expenses: $30,000

Entertainment $8,000
Penalties and fines $2,000
Depreciation (accounting) $20,000

Adjusted profit: $180,000
Less: Capital allowances (tax) ($20,000)

Chargeable income: $160,000

This chargeable income is what gets taxed at 17% (before exemptions).

Supporting Documents

Keep these documents organised and accessible:

Income documentation:

Sales invoices
Bank statements showing receipts
Contracts or agreements
Proof of other income (interest, dividends, rental)

Expense documentation:

Purchase invoices
Supplier statements
Receipts for business expenses
Proof of payment (bank statements, cheque images)
Employment contracts and payslips for staff costs
CPF contribution records

Asset documentation (for capital allowances):

Purchase invoices for equipment, machinery, computers
Delivery orders
Asset register showing acquisition dates and costs
Hire purchase or lease agreements

Other important documents:

Resolutions or AGM approving the director’s remuneration
Related party transaction documentation
Loan agreements
Rental agreements

You will be able to find the latest [tax computation templates] on IRAS’s website (https://www.iras.gov.sg/quick-links/calculators)

Access to myTax Portal

You'll need the right access credentials to file online.

What you need:

For company representatives:

CorpPass account (for company access). You can request for the CorpPass admin to give you access the “Corporate Tax (Filing and Application)” service.

For tax agents:

Tax Agent Portal access
Proper authorisation from company

Setting up access:

Company secretary or director registers for CorpPass
Log in to myTax Portal using CorpPass
If this service has not been selected for the Company: i. the CorpPass admin can login to [corppass website] (https://www.corppass.gov.sg/portal) ii. Under "e-Service", select "Select Entity's e-Service". In the search field, search "IRAS". Select “Corporate Tax (Filing and Application)”
Assign service to user

First-time filing:

Allow extra time to set up access
Test login before deadline approaches
Update contact details in myTax Portal

Information Specific to Each Form Type

Different forms require different levels of detail.

Form C-S (Lite) additional requirements:

Revenue figure
Basic tax computation
Answers to shareholding questions
Startup exemption status (if applicable)

Form C-S additional requirements (beyond C-S Lite):

Gross profit/loss breakdown
Directors' fees and remuneration (total amount)
Staff costs excluding directors
Specific expense categories:
- Medical Expenses (Deductible amount)
- Transport/travelling expenses
- Research & development costs (if claiming enhanced deductions)
Balance sheet items:
- Inventories
- Trade receivables amount

Form C additional requirements (beyond C-S):

Detailed breakdown of all revenue sources
Complete expense schedules by category
Full balance sheet
Cash flow statement (for larger companies)
Related party transaction details
Group relief claims documentation
Foreign tax credit computation
Supporting schedules for all claims

Capital Allowances Documentation

If claiming capital allowances, prepare:

Asset register:

Description of each asset
Date of acquisition
Cost of acquisition
Accumulated capital allowances claimed
Written down value

Capital allowance computation:

Assets qualifying for allowances
Allowance rates (1-year, 3-year, or specific rates)
Current year claims
Unutilised allowances brought forward
Balancing charges (if asset sold)

Common capital allowance rates:

Computers and software: 100% (1-year write-off)
Office equipment, furniture: 33.33% per year (3-year write-off)
Motor vehicles: 20% per year (5-year write-off)
Renovation: 33.33% per year (3-year write-off, capped at $300,000)

Special Situations: Additional Documentation

If claiming startup exemption (SUTE):

Certificate of Incorporation
Confirmation that all conditions met
Shareholding records

If you have foreign income:

Foreign income statements
Foreign tax paid documentation
Exchange rate used for conversion

If in a group structure:

Group structure chart
Related company financial statements (for group relief)
Transfer pricing documentation
Intra-group transaction records

If you changed business activities:

Documentation explaining the change
Reason for change in principal activities
Impact on prior year losses carried forward

Checklist: Are You Ready to File?

Use this checklist before starting your tax return:

Financial documents:

[ ] Profit & Loss statement finalised
[ ] Balance sheet finalised
[ ] Notes to accounts prepared
[ ] Directors approved financial statements

Tax computation:

[ ] Tax computation worksheet completed
[ ] Non-deductible expenses identified and added back
[ ] Capital allowances calculated
[ ] Chargeable income determined

Supporting documents:

[ ] All invoices and receipts organised
[ ] Bank statements available
[ ] Asset register updated
[ ] Employment records (for staff costs)

Access and authorisation:

[ ] CorpPass/Singpass access working
[ ] Can log into myTax Portal
[ ] Tax agent authorised (if using one)

Form-specific information:

[ ] Determined correct form (C-S Lite, C-S, or C)
[ ] Required financial details ready for your specific form
[ ] Special claims documented (if applicable)

Deadlines:

[ ] Know your ECI deadline
[ ] Know your Form C/C-S deadline
[ ] Sufficient time before deadline

If you've ticked all applicable boxes, you're ready to file.

How Long Does Filing Take?

Filing time varies significantly based on: • Your familiarity with the form • Complexity of your business • How organized your documents are • Whether you're using tax software

If you're well-prepared with all documents ready, the actual data entry in myTax Portal may take 1-2 hours. However, gathering information and preparing tax computation typically takes much longer. Factors that increase time:

First time filing this form type
Complex group structures
Foreign income or tax credits
Multiple revenue sources
Large number of expense categories
Capital allowance calculations

Time-saving tip: Prepare all documents before you start filing online. The myTax Portal session may time out if you take too long searching for information.

What If You're Missing Documents?

If you discover missing documents after starting to file:

Don't guess or estimate - inaccurate filing can trigger IRAS review
Save your progress in myTax Portal (if form allows)
Obtain the missing documents before completing submission
Request extension from IRAS if deadline approaching and documents unavailable

If financial records are incomplete (e.g. you don’t have a financial statements):

Prepare the accounting general ledger, trial balance, balance sheet and P&L by starting from the bank statements
check the tax deductibility of the expenses
use the tax template from IRAS to help you prepare the tax computation
Consider engaging professional help to reconstruct records

Proper preparation eliminates stress during filing and reduces errors that could trigger IRAS queries. If gathering these documents feels overwhelming, our tax filing service handles all preparation and documentation, ensuring complete and accurate submissions.

Common Tax Deductions for SMEs

Understanding what expenses are tax-deductible can significantly reduce your corporate tax bill. This section covers the most common deductions Singapore SMEs can claim.

General Rule for Tax Deductibility

For an expense to be tax-deductible, it must meet three conditions:

Wholly and exclusively incurred in the production of income - The expense must be for business purposes, not personal use
Revenue in nature - Operating expenses, not capital expenditure (which qualifies for capital allowances instead)
Not specifically prohibited by law - IRAS specifically disallows certain expenses regardless of business purpose

Staff Costs (Fully Deductible)

Employee-related expenses are among the most straightforward deductions.

Salaries and wages:

Basic salary
Overtime pay
Bonuses (including performance bonuses, AWS, variable bonuses)
Commissions
Allowances (transport, mobile, meal)

CPF contributions:

Employer's CPF contributions for employees
Must be actually paid to CPF Board to claim

Staff benefits:

Medical and dental benefits
Insurance premiums for employees
Training and development courses
Staff welfare expenses (team building, meals)

Foreign worker levies:

Work permit levies paid to MOM

Important: Directors' fees are deductible, but must be approved at AGM and actually paid or accrued in the year of claim.

Rental Expenses

Office rental:

Monthly rent payments
Service charges
Property tax (if borne by tenant)

Equipment rental:

Photocopier leases
Computer equipment rental
Vehicle rental (for business use)

Important: Security deposits are not deductible when paid - only deductible if forfeited.

Utilities and Telecommunications

Fully deductible:

Electricity
Water
Gas
Internet and broadband
Mobile phone bills (business use)
Fixed line telephone

Partial deduction: If premises used for both business and personal purposes (e.g., home office), only the business portion is deductible.

Professional and Consultancy Fees

Legal and professional fees:

Accounting fees
Tax filing fees
Legal fees for business matters (contracts, debt collection, employment issues)
Consultancy fees
Audit fees

Not deductible:

Legal fees for capital transactions (e.g., acquisition of business, property purchase)
Fines and penalties

Insurance Premiums

Deductible insurance:

Fire and theft insurance for business premises
Public liability insurance
Professional indemnity insurance
Product liability insurance
Key person insurance (if company is beneficiary)
Medical insurance for employees

Not deductible:

Life insurance where individual is beneficiary
Personal accident insurance for directors where family members are beneficiaries

Repairs and Maintenance

Deductible:

Repairs to business premises
Repairs to equipment and machinery
Maintenance contracts
Servicing of vehicles

Not deductible (capital in nature):

Renovations that enhance the asset
Replacement of major components
Upgrades that improve functionality

However, certain renovation costs up to $300,000 qualify for Renovation and Refurbishment deductions and certain capital repairs would allow to claim capital allowances.

Transportation and Motor Vehicle Expenses

If company owns the vehicle: Capital allowances may apply for commercial vehicle cost.

Operating expenses deductible:

Petrol and diesel
Road tax
Insurance
Parking fees (business-related)
ERP charges
Repairs and servicing
Vehicle inspection fees

Not deductible:

Personal use portion (must apportion)
Parking fines and traffic violations

If using personal vehicle for business:

Claim mileage allowance or actual expenses with proper apportionment
Keep mileage log to support business use percentage
Passenger vehicle costs are disallowed

Marketing and Advertising

Fully deductible:

Online advertising (Google Ads, Facebook Ads, LinkedIn)
Print advertising (newspapers, magazines)
Outdoor advertising (billboards, bus ads)
Marketing materials (brochures, flyers, name cards)
Website development and maintenance
Social media marketing
Trade show and exhibition costs
Sponsorships (for business promotion purposes)

Partially deductible:

Corporate gifts up to $200 per recipient per year
Gifts exceeding $200 not deductible

Technology and Software

Revenue expenses (fully deductible):

Software subscriptions (SaaS - Xero, QuickBooks, Microsoft 365)
Cloud storage fees
Domain name renewal
Website hosting
IT support and maintenance
Anti-virus and security software subscriptions

Capital expenses (capital allowances apply):

Purchase of computers and laptops
Software licenses purchased outright
Servers and networking equipment

Office Supplies and Equipment

Fully deductible:

Stationery and printing supplies
Postage and courier fees
Cleaning supplies and services
Pantry supplies (coffee, tea, water)
Small equipment under $5,000 per item

Capital allowances apply:

Furniture and fittings
Office equipment
Computers, handphones, CCTV etc

Bank Charges and Interest

Deductible:

Bank account fees
Transaction charges
Interest on business loans
Interest on hire purchase for business assets
Overdraft interest

Not deductible:

Interest on capital introduced by shareholders
Late payment interest and penalties on taxes

Entertainment Expenses (Deductible)

Not deductible if:

Personal (non-business related). You will need to explain the person, position and company you entertained

Travel Expenses

Deductible business travel:

Air tickets
Accommodation
Transport at destination
Meals during travel
Conference and seminar fees
Travel insurance

Must be business-related: Keep documentation showing business purpose (meeting notes, conference agenda, etc.)

Not deductible:

Personal travel
Family members accompanying on business trip (their costs)
Extended stay for personal reasons (personal portion)

Donations

Tax-deductible donations (2.5× deduction):

Donations to approved Institutions of a Public Character (IPCs)
Must have tax deduction receipt from IPC
Enhanced deduction: Every $1 donated = $2.50 deduction

Example: Donate $10,000 to approved IPC → $25,000 deduction from chargeable income.

Not deductible:

Donations to non-approved organizations
Donations without proper receipts
Political donations

Check IPC status: Verify charity is IPC-approved on IRAS website before donating.

Research & Development (R&D)

Enhanced deduction for qualifying R&D:

150% deduction for staff costs (Singapore-based R&D)
100% deduction for other qualifying R&D expenditure

What qualifies:

R&D undertaken in Singapore
Systematic investigation or experimentation
Advancement of science or technology
Resolves scientific or technological uncertainty

Staff costs qualifying for 150%:

Salaries of R&D employees
CPF contributions
Must be directly engaged in R&D activities in Singapore

Other qualifying R&D costs:

Consumables used in R&D
Payments to R&D service providers
Costs of materials for R&D

Important: Must be registered under Section 14DA scheme or claim under automatic inclusion (Section 14E).

Renovation and Refurbishment (Section 14N)

Capped at $300,000 qualifying expenditure per 3-year period

What qualifies:

Renovation of business premises
Refurbishment of business premises
Must be incurred on premises used for trade/business

What doesn't qualify:

Purchase of furniture and fittings (separate capital allowance)
Structural alterations
Renovation of residential premises

Intellectual Property (IP) Rights

Enhanced deductions and allowances:

Writing-Down Allowances (WDA) for IP:

100% write-off over 5 years (20% per year) or
100% write-off over 10 years (10% per year) - taxpayer's choice

Qualifying IP:

Patents
Copyrights
Trademarks
Registered designs
Plant varieties
Trade secrets or information
Know-how

IP registration costs:

Legal fees for IP registration (deductible or capital allowance)
Application fees (deductible or capital allowance)

What You CANNOT Deduct

Examples of explicitly prohibited expenses:

Capital expenditure:

Purchase of assets (equipment, property, vehicles)
Use capital allowances instead

Personal expenses:

Directors' personal expenses
Personal insurance
Home expenses unrelated to business

Fines and penalties:

Traffic fines
IRAS penalties
Government fines and penalties
Late payment charges to government agencies

Specific statutory prohibitions:

Private car expenses (unless qualifying criteria met)
Domestic and personal expenses
Non-trade losses
Taxes on income (corporate tax, income tax)

Strategic Deduction Planning

Maximise deductions legally:

Timing of expenses:

Incur deductible expenses before FYE to claim in current year
Defer income where possible to smooth tax liability

Choose enhanced deduction schemes:

R&D activities (150% on staff costs)
Renovation (300% deduction up to $300K)
Donations to IPCs (250% deduction)

Proper documentation:

Keep all receipts and invoices
Document business purpose for expenses
Maintain expense approval process
Segregate business vs personal expenses

Common mistakes to avoid:

Claiming capital expenses as revenue expenses
Insufficient documentation for deductions
Mixing personal and business expenses
Missing enhanced deduction opportunities

How Deductions Reduce Your Tax Bill

Example calculation: Revenue: $500,000 Less: Cost of goods sold: ($200,000) Gross profit: $300,000 Less: Operating expenses: Staff costs $80,000 Rental $36,000 Marketing $20,000 Professional fees $15,000 Utilities $6,000 Other expenses $23,000 ($180,000)

Net profit (accounting): $120,000 Add: Non-deductible expenses: Entertainment $5,000 Depreciation (replaced by CA) $10,000 $15,000

Adjusted profit: $135,000 Less: Capital allowances: ($15,000)

Chargeable income: $120,000 Less: Tax exemptions (SUTE): First $100K @ 75% exempt ($75,000) Next $20K @ 50% exempt ($10,000)

Taxable income: $35,000 Tax @ 17%: $5,950 Every dollar of legitimate deduction reduces your tax by 17 cents (before exemptions).

Need Help Identifying Deductions?

Many SMEs under-claim deductions simply because they're unaware of what's allowable.
Refer to our [SME deductible expenses guide] (/articles/sme-deductible-expenses-guide) for more details.
Our tax filing service includes a comprehensive review of your expenses to ensure you claim every deduction you're entitled to, maximising your tax savings while staying fully compliant.

Step-by-Step Filing Process

This section focuses on navigating the myTax Portal and completing your Form C-S or C-S (Lite) submission. We'll cover the filing mechanics, highlight confusing fields, and explain what happens after you submit. You can also refer to [IRAS’s guide] (https://www.iras.gov.sg/media/docs/default-source/uploadedfiles/pdf/user-guide-(tp)_file-form-c-sfb87cf1c-ae51-4063-802b-e57454d68147.pdf?sfvrsn=bf08a50e_29)

Before You Start Filing

Ensure you have completed:

Tax computation (refer to the tax computation preparation discussed earlier)
Identified all deductible expenses (see Common Tax Deductions)
Determined which form applies to you (see Types of Tax Forms)
Gathered all required information (see What You Need Before Filing)

Technical requirements:

Stable internet connection
CorpPass login credentials
Modern web browser (Chrome, Firefox, Safari, Edge)
1-2 hours of uninterrupted time

Tip: The myTax Portal session may time out after 20-30 minutes of inactivity. Have all information ready before logging in to avoid losing progress.

Accessing myTax Portal

Step 1: Navigate to myTax Portal

Go to https://mytax.iras.gov.sg/login/selection
Select “Company/Business Tax”
Click "Login"

Step 2: Authenticate

Complete 2FA authentication (SMS OTP or Singpass app)
If you have access to multiple entities, select the correct company

Step 3: Navigate to tax filing

From the myTax homepage, under the header bank, select "Corporate Tax" > Select “file Form C-S/C"
Choose the Year of Assessment you're filing for
System will show available filing options based on your company's profile

Tip: If you don't see the filing option, check that you're filing for the correct YA and that the filing period is open (typically opens around August for 30 November deadline).

Completing the Tax Return

Step 1: Form selection Enter your company’s revenue in the field. If below $200,000, the page will prompt to select Form C-S Lite or Form C-S For Form C-S (Lite) qualification:

Revenue $200,000 or below?
Only income taxed at 17%?
Not claiming carry-back, group relief, investment allowance, or foreign tax credit?

For Form C-S qualification:

Revenue $5 million or below?
Only income taxed at 17%?
Not claiming the four excluded items?

The system routes you to the appropriate form based on your answers and may prevent you from filing the wrong form.

Step 2: Confirm company details

Review pre-filled information:

Company name and UEN
Registered address
Principal business activity code
Financial year end

Important: If any details are incorrect (especially FYE), you must update your company profile first before proceeding. Incorrect FYE will cause filing errors.

Step 3: Declare financial period

Enter your financial year dates:

Financial period start date
Financial period end date

If you prepared multiple sets of accounts (e.g., change of FYE during the year):

Indicate "Yes" when asked
Enter the FYE of the first set of accounts
The system will ask for details of both periods

This is uncommon for most SMEs. If your company had a standard 12-month financial year with no changes, select "No."

Part A: Qualifying Conditions

The system pre-fills your answers from the initial qualifying questions. Review and confirm:

Review person question: "Has the return been reviewed by a Singapore Chartered Tax Professionals Limited (SCTP) Accredited Tax Advisor or Accredited Tax Practitioner for Income Tax?"

Answer "No" if you're filing yourself
Answer "Yes" if your tax agent reviewed it (they'll provide their details)

This does NOT mean you need professional review to file. It's asking IF a professional reviewed it, not requiring that one did.

Part B: Tax Adjustments

This section captures your tax computation. Enter figures from your completed tax computation worksheet.

Fields are straightforward, but watch out for these:

1. Net Profit/Loss before Tax as per Financial Statements

Enter the exact figure from your P&L bottom line
Negative number if loss (the system accepts negative values)
Round off to nearest dollar

2. Non-Tax Deductible Expenses

This is the total you calculated when adding back non-deductible items
Includes: entertainment, depreciation, fines, personal expenses, etc.
Refer to your tax computation worksheet for the total

3. Balancing Charge

Only applies if you sold or disposed of an asset during the year for more than its written-down value
Most companies enter $0 here
If you sold equipment/machinery at a gain, you need to calculate the balancing charge

Tip: Balancing charge is complex. If you disposed of assets, consult the IRAS guide on balancing charges or seek professional help to calculate correctly.

4. Unutilised Capital Allowances brought forward

From your previous year's tax return
Found on prior year's NOA or Form C-S acknowledgement
Enter $0 if this is first year of operation or no unutilised amounts from prior year

5. Current Year Capital Allowances

Total capital allowances you're claiming this year
Calculated based on assets acquired and IRAS prescribed rates
Refer to your capital allowance schedule

6. Unutilised Losses brought forward

From previous year's tax return
Only if you had losses in prior years that weren't fully utilised
Enter $0 if first year or no prior losses

Separate Source Income section:

Net Rental Income: Rental income minus rental expenses
Interest Income: Bank interest, loan interest received
Other Taxable Income: Any other income not in your main business revenue

Most trading companies enter $0 for all three unless they have property rental or significant interest income.

Donations:

Unutilised Donations brought forward: From prior year's return
Current Year Donations: Actual cash donated to IPCs × 2.5

The system auto-calculates:

Adjusted profit
Total income before and after donations
Carried forward amounts

Verify the calculated figures match your worksheet before proceeding.

Part C: Information from Financial Statements

This section varies significantly between Form C-S (Lite) and Form C-S.

Fields common to both forms:

1. Revenue

Total revenue from your financial statements
Must match the revenue figure in your P&L and what you entered when you selected the form
This is a key verification field - IRAS cross-checks this

2. Deduction for Renovation or Refurbishment Works (Section 14N)

Leave blank if not claiming or no renovation costs

3. R&D Deductions (Section 14C)

Total qualifying R&D expenditure
Breakdown by Singapore vs overseas R&D
Staff costs qualifying for 150% deduction
Leave blank if no R&D activities

Most SMEs are NOT claiming R&D deductions. Don't enter anything here unless you specifically conducted qualifying R&D and are claiming enhanced deductions.

4. Change in principal activities during the basis period?

Answer "Yes" only if you fundamentally changed what your business does
Example: Changed from retail to F&B operations
Affects whether you can use unutilised losses from prior years
Most companies answer "N.A." or "No"

5. Substantial change in company's ultimate shareholders?

Answer "Yes" only if more than 50% of shareholding changed hands
Example: Sold majority stake to new investor
Affects unutilised loss utilisation
Most SMEs answer "N.A." or "No"

Tip: The shareholding questions have technical definitions. If in doubt, answer "N.A." (not applicable) rather than guessing. Wrong answers could disqualify you from using prior losses.

6. Tax Exemption Scheme for New Start-up Companies

Answer "Yes" only if your company qualifies for SUTE
Conditions: First 3 YAs, all shareholders are individuals throughout basis period, etc.
If you don't qualify or are beyond first 3 years, answer "No"

The system applies the correct exemption (SUTE or PTE) based on your answer.

7. Appropriation of Trading Stock or Conversion of Non-Trade/Capital Asset

Only answer "Yes" if you transferred trading stock to non-trade use or vice versa
Example: Took inventory for personal use
Rare for most companies - typically answer "No"

8. Enterprise Innovation Scheme (EIS) claims

Training, Innovation Projects, IPR Acquisition, IPR Licensing, R&D
Only complete if you're specifically claiming EIS benefits
Each section asks for qualifying cost and enhanced deduction claimed
Most SMEs leave all EIS sections at $0

Additional fields for Form C-S only:

9. Gross Profit/Loss

Revenue minus cost of goods sold
From your P&L statement
For service businesses with no COGS, this equals revenue

10. Directors' Fees and Remuneration

Total directors' fees paid or accrued during the year
Include salaries, bonuses, fees for directors
Must match what's in your financial statements

11. Total Remuneration excluding Directors' Fees

Salaries and wages for non-director employees
Include bonuses, allowances, overtime
Employer CPF contributions
Exclude directors' remuneration (captured separately above)

12. Transport/Travelling Expenses

Business travel costs
Staff transport allowances
Petrol, parking, toll charges
From your expense breakdown

13. Trade Receivables

Amount owed to you by customers as at FYE
From your balance sheet (current assets)
Include only trade debtors, not other receivables

Tip: Part C figures must match your financial statements exactly. IRAS may cross-check, and discrepancies trigger queries.

Review and Submit

Before clicking Submit:

1. Review estimated tax payable

The system calculates: Estimated Tax Payable: $X,XXX.XX This should roughly match your own calculation. If it's wildly different:

Check if correct exemption scheme applied (SUTE vs PTE)
Verify capital allowances entered correctly
Ensure no fields were left blank by mistake

2. Common reasons for unexpected tax amounts:

Wrong exemption: SUTE applied when PTE should apply (or vice versa)
Missed capital allowances: Forgot to enter current year allowances
Wrong revenue figure: Typo in revenue amount
Unutilised amounts not brought forward: Forgot prior year's unutilised losses/allowances

3. Declaration

Tick the declaration box confirming:

The return gives full and true account of company's income
Information provided is accurate

4. Enter filer details:

Name of filer
Designation (Director, Company Secretary, Tax Agent)
Contact number
Email address (where acknowledgement will be sent)

5. Click "Submit"

The system processes immediately and displays:

Acknowledgement number
Date and time of submission
Summary of your filing

6. Download acknowledgement

Save the acknowledgement PDF:

Contains full summary of what you submitted
Your proof of filing
Needed if IRAS queries your return
Store in company records for at least 5 years

An acknowledgement email is sent to the registered email address automatically.

What to Do After Submission

Immediate actions:

1. Save all documents

Acknowledgement PDF
Tax computation worksheet
Financial statements
Supporting documents (invoices, receipts, bank statements)
Capital allowance schedules

Retention period: 5 years from the YA

2. Update your records

Note down unutilised amounts carried forward (for next year's filing)
Update asset register with current year capital allowances claimed
File acknowledgement in corporate records

3. Wait for Notice of Assessment (NOA)

IRAS will review your return and issue NOA:

Timeline:

Simple returns (C-S Lite, straightforward C-S): 1-3 months
Complex returns: 2-4 months
First-time filings: May take longer
Returns selected for review: 3-6 months

What the NOA contains:

Final tax assessed
Amount payable
Payment deadline (typically 1 month from NOA date)
Payment methods

4. If IRAS requests additional information

IRAS may query your return and request:

Supporting documents
Clarification on specific items
Tax computation breakdown

Response deadline: Usually 14-30 days from request date

How to respond:

Via myTax Portal "Submit Document" function
Upload requested documents
Provide clear explanations
Meet the deadline (late response may result in estimated assessment)

Tip: IRAS requesting information doesn't mean you did something wrong. It's routine for certain transactions or first-time filings. Respond promptly and completely.

5. When you receive NOA

Review the NOA:

Check if assessed tax matches your estimated tax
Verify exemptions applied correctly
Ensure IRAS didn't make adjustments you disagree with

If NOA is correct:

Pay tax by deadline stated
Payment methods: GIRO, internet banking, AXS, cheque

If NOA is incorrect:

File Notice of Objection within 30 days of NOA date
State clearly what's wrong and provide supporting documents
IRAS will review and issue revised assessment if they agree

Payment deadline: Within 1 month of NOA date

Late payment penalties:

5% penalty immediately upon default
Additional 1% per month (capped at 12%)

Monthly instalment option:

Set up GIRO to pay over 12 months interest-free
Must set up before tax is due
Apply via myTax Portal

Common Filing Errors and How to Fix Them

Error 1: "You are not authorised to file for this company"

Cause: Insufficient access rights in CorpPass

Solution:

Contact company admin to grant you filing authorisation
Admin logs into CorpPass → Manage Users → Add filing rights for Corporate Tax

Error 2: "Financial year dates do not match our records"

Cause: IRAS has different FYE in their system

Solution:

Update company profile first via "Update Corporate Profile"
Then return to file tax return
If FYE genuinely changed, indicate multiple sets of accounts

Error 3: "Validation error - mandatory field missing"

Cause: Skipped required fields

Solution:

Scroll through entire form
System highlights missing fields in red
Common misses: Shareholding questions, SUTE questions, filer contact details

Error 4: "Tax computation does not balance"

Cause: Auto-calculated fields don't match expected results

Solution:

Review each line item
Common error: Capital allowances entered in wrong field
Double-check unutilised amounts brought forward
Verify additions and subtractions

Error 5: System timeout

Cause: Inactive for 20-30 minutes

Solution:

Some forms allow "Save Draft" - use this if available
Otherwise, have all information ready before starting
Complete filing in one session

Tip: If you encounter technical errors with myTax Portal, call IRAS helpline at 1800 356 8300 (Mon-Fri 8am-5pm). Have your company UEN ready.

What If You Made a Mistake After Submitting?

You cannot edit a submitted return. Once submitted, it's locked.

Options to correct errors:

Option 1: Wait for NOA, then file objection

IRAS issues NOA based on your filed return
If you spot error, file Notice of Objection within 30 days
Explain the error and provide corrected figures
IRAS reviews and issues revised assessment

Option 2: Contact IRAS immediately

Call IRAS or submit query via myTax Portal
Explain the error before NOA is issued
IRAS may allow amended filing in some cases

Option 3: File amended return (if IRAS approves)

IRAS must authorise an amended return
Not automatically allowed
Usually only for significant errors

Common post-filing mistakes:

Forgot to claim capital allowances
Applied wrong tax exemption scheme
Arithmetic errors in computation
Missed deductions

Most errors can be corrected through objection after receiving NOA, but it's better to file correctly the first time.

Filing Checklist

Before clicking "Submit," verify:

[ ] Correct Year of Assessment selected
[ ] Financial period dates match your actual FYE
[ ] Correct form selected (C-S Lite vs C-S vs C)
[ ] Tax computation figures match your worksheet
[ ] Revenue matches financial statements exactly
[ ] Part C additional info (gross profit, directors' fees, etc.) matches financial statements
[ ] Capital allowances calculated correctly
[ ] Unutilised amounts from prior year entered correctly (if applicable)
[ ] All shareholding questions answered appropriately
[ ] SUTE/PTE selection is correct
[ ] No mandatory fields left blank
[ ] Estimated tax payable seems reasonable
[ ] Filer contact details correct
[ ] Declaration box ticked
[ ] All supporting documents saved and accessible

If everything checks out, submit confidently.

The filing process is straightforward when you're well-prepared. However, if you'd prefer professional handling to ensure accuracy and avoid errors, our tax filing service manages the entire process from tax computation to submission, giving you peace of mind and freeing you to focus on your business.

Common Mistakes to Avoid

Even experienced business owners make errors when filing corporate tax returns. This section highlights the most common mistakes and how to avoid them.

Mistake 1: Missing the Filing Deadline

The error: Assuming 30 November is a soft deadline or that IRAS will automatically grant extensions.

Why it happens:

Business owners prioritise operations over compliance
Waiting until last minute to gather documents
Underestimating time needed to prepare return

Consequences:

$200 minimum penalty for late filing
Up to $1,000 for repeated offences
IRAS may issue estimated assessment (often higher than actual tax)
Penalties accumulate if filing remains outstanding

How to avoid:

Set internal deadline of 31 October (one month buffer)
Prepare financial statements immediately after FYE
File ECI on time (don't skip this just because you're exempt)
Use calendar reminders for key dates

Tip: IRAS does NOT send filing reminders. You're expected to know and meet deadlines. Mark 30 November in your calendar every year, regardless of your FYE.

Mistake 2: Filing the Wrong Form

The error: Filing Form C-S when you should file Form C, or vice versa.

Why it happens:

Misunderstanding revenue thresholds
Not realising certain claims disqualify you from C-S
Assuming same form as previous year applies

Consequences:

IRAS rejects filing and requires correct form
Delays in processing
May miss deadline whilst correcting
Additional scrutiny on future filings

How to avoid:

Check qualifying conditions EVERY year (see Types of Tax Forms)
Don't assume: revenue might have exceeded $5M, or you might be claiming group relief this year
Answer qualifying questions in myTax Portal honestly
Review prior year circumstances that may have changed

Red flag scenarios:

Revenue exceeded threshold by year-end (even if you estimated lower in ECI)
Claiming foreign tax credit for the first time
New group structure allowing group relief
Carrying back losses from current year to prior year

Mistake 3: Misclassifying Capital vs Revenue Expenses

The error: Deducting capital expenditure as revenue expense, or vice versa.

Why it happens:

Confusion about what qualifies as capital expenditure
Aggressive tax planning without proper understanding
Following accounting treatment instead of tax treatment

Consequences:

IRAS disallows deduction during review
Revised assessment with additional tax payable
Potential penalties for incorrect filing
Interest charges on additional tax

How to avoid:

Revenue expenses (deductible immediately):

Repairs and maintenance
Minor equipment under $5,000
Software subscriptions (SaaS)
Consumables and supplies

Capital expenses (claim capital allowances instead):

Purchase of equipment, machinery, computers
Renovations enhancing the asset
Furniture and fittings
Motor vehicles
Software licenses purchased outright

Tip: When in doubt, apply the "enhancement test." If the expense enhances or improves the asset beyond its original condition, it's likely capital. If it merely maintains or restores, it's revenue.

Grey area - Renovation:

Simple repairs and repainting: Revenue expense (deductible)
Major renovation changing layout/function: Capital expense (claim capital allowances)

Refer to our SME deductible expenses guide for detailed examples.

Mistake 4: Incorrect Capital Allowance Calculations

The error:

Claiming 100% write-off for assets that only qualify for 33.33%
Using wrong asset life
Forgetting to claim capital allowances entirely
Claiming more than adjusted profit allows

Why it happens:

Misunderstanding IRAS prescribed rates
Not maintaining proper asset register
Confusion about balancing charges when assets sold

Consequences:

Under-claiming: Pay more tax than necessary
Over-claiming: IRAS disallows, additional tax payable
Wrong rate used: Computation errors trigger review

How to avoid:

Know the correct rates:

Computers, software, prescribed automation equipment: 100% (year 1)
Office equipment, furniture, renovation: 33.33% per year (3 years)
Motor vehicles: 20% per year (5 years)
Industrial machinery: Varies by type

Maintain asset register:

Date acquired
Cost
Capital allowances claimed each year
Written-down value
Disposal details (if sold)

Don't claim more than you can use:

Capital allowances cannot create a loss (unless you have unutilised allowances from prior years)
Excess becomes unutilised capital allowances carried forward

Tip: Create a simple Excel spreadsheet tracking each asset's cost, accumulated allowances, and remaining written-down value. Update it annually when filing tax.

Mistake 5: Claiming Non-Deductible Expenses

The error: Deducting expenses that IRAS specifically prohibits.

Why it happens:

Assuming all business expenses are deductible
Following accounting treatment without checking tax rules
Including personal expenses in business claims

Common non-deductible items wrongly claimed:

Entertainment expenses (client meals, corporate gifts over $200)
Fines and penalties (traffic fines, IRAS penalties, late fees)
Personal expenses charged to company
Capital expenditure (deducted as revenue)
Provisions not yet incurred (e.g., warranty provisions)
Personal insurance where director/family is beneficiary

Consequences:

IRAS adds back during review
Additional tax payable
Penalties if deemed aggressive or deliberate

How to avoid:

Review Common Tax Deductions section carefully
When unsure, check IRAS e-Tax guides
Keep detailed expense descriptions (not just "miscellaneous")
Separate personal and business expenses clearly

Mistake 6: Forgetting Unutilised Amounts from Prior Years

The error: Not bringing forward unutilised capital allowances, losses, or donations from previous years.

Why it happens:

Poor record-keeping
Didn't review prior year's tax return
First year using new accountant/tax agent who doesn't have history

Consequences:

Pay more tax than necessary
Lose tax savings you're entitled to
Carry forward amounts indefinitely, but missing them now means higher current tax

How to avoid:

Check prior year's Notice of Assessment (NOA)
Review prior year's Form C-S acknowledgement
Look for these specific amounts:
- Unutilised capital allowances carried forward
- Unutilised losses carried forward
- Unutilised donations carried forward
Enter these in Part B of current year's return

Tip: Create a "tax carry-forward schedule" noting these amounts each year. Store it with your tax files so it's easy to find next filing season.

Where to find prior year amounts:

Previous year's NOA (final section)
Previous year's Form C-S acknowledgement (Part B)
Previous year's tax computation worksheet

Mistake 7: Wrong Tax Exemption Scheme Applied

The error: Claiming Startup Tax Exemption (SUTE) when not eligible, or not claiming it when eligible.

Why it happens:

Misunderstanding SUTE qualifying conditions
Not tracking which Year of Assessment company is in
Shareholder changes during the year disqualifying SUTE

SUTE conditions (all must be met):

Company incorporated in Singapore
Tax resident in Singapore
First 3 consecutive Years of Assessment
All shareholders are individuals throughout basis period (no corporate shareholders)
Shareholding held beneficially (not as nominees)

Consequences of wrong application:

Claim SUTE when ineligible: IRAS revises assessment, additional tax payable
Don't claim SUTE when eligible: Pay more tax than necessary

How to avoid:

Check incorporation date to confirm YA count
Review shareholder register throughout financial year
If any corporate shareholder at any time during year: SUTE disqualified
If beyond YA 3: Use Partial Tax Exemption (PTE) instead

YA counting example:

Incorporated: 15 March 2022
YA 1: 2023 (for FYE in calendar 2022)
YA 2: 2024 (for FYE in calendar 2023)
YA 3: 2025 (for FYE in calendar 2024)
YA 4 onwards: 2026+ (use PTE)

Mistake 8: Inaccurate Revenue Figure

The error: Revenue entered in tax return doesn't match financial statements.

Why it happens:

Typo when entering figures
Including GST in revenue (should be GST-exclusive)
Using cash basis instead of accrual basis
Estimating instead of using actual audited figures

Consequences:

IRAS queries and requests financial statements
Delays in assessment
If significantly understated: Penalties for incorrect return
If overstated: Pay more tax than necessary

How to avoid:

Enter revenue EXACTLY as shown in P&L statement
For GST-registered companies: Use GST-exclusive revenue
Double-check the figure before submitting
Don't round to nearest thousand unless financial statements also rounded

Tip: Revenue is a key verification field. IRAS may cross-check with GST returns, industry benchmarks, and prior years. Ensure accuracy.

Mistake 9: Not Keeping Proper Supporting Documents

The error: Filing tax return without retaining invoices, receipts, and supporting documents.

Why it happens:

Thinking IRAS doesn't need documents since they're not submitted
Poor document organisation
Assuming "no audit means no documents needed"

Consequences:

IRAS can request documents up to 5 years after YA
Cannot substantiate deductions if documents missing
IRAS may disallow deductions entirely
Penalties for non-compliance with record-keeping requirements

What to keep (5-year retention):

All sales invoices and receipts
All purchase invoices and expense receipts
Bank statements
Employment records (contracts, payslips, CPF statements)
Asset purchase documentation
Loan agreements
Rental agreements
Financial statements and tax computations

How to avoid:

Digitise documents immediately (photo or scan)
Organise by financial year and category
Use cloud storage (Google Drive, Dropbox) with backups
Keep both digital and physical copies if possible

Mistake 10: Ignoring IRAS Queries

The error: Not responding to IRAS requests for information or clarification.

Why it happens:

Didn't see the notification (wrong email address)
Procrastination or hoping it goes away
Don't have requested documents readily available

Consequences:

IRAS issues estimated assessment (usually unfavourable)
Penalties for non-compliance
Additional scrutiny on future filings
Potential audit

How to avoid:

Ensure correct email address in myTax Portal profile
Check myTax Portal regularly for messages (don't rely only on email)
Respond within deadline stated (usually 14-30 days)
If you need more time, contact IRAS immediately to request extension

Tip: IRAS queries are routine for certain transactions or first-time filings. They don't automatically mean you did something wrong. Respond promptly and completely to avoid escalation.

When IRAS requests information:

Read the query carefully to understand what they need
Gather requested documents
Provide clear explanations
Submit via myTax Portal "Submit Document" function
Keep copy of what you submitted

Mistake 11: DIY When Situation is Complex

The error: Attempting to file yourself when your tax situation requires professional expertise.

Why it happens:

Wanting to save accountant fees
Underestimating complexity
Overconfidence from filing simple returns previously

When DIY becomes risky:

You should consider professional help if:

First year of business (setting up systems correctly matters)
Revenue exceeds $1M (higher tax amounts mean bigger consequences if wrong)
Related party transactions (transfer pricing issues)
Group structures (group relief, consolidation issues)
Foreign operations or foreign tax credits
Complex asset disposals with balancing charges
Restructuring or business acquisition during year
Claiming specialised deductions (R&D, IP allowances, etc.)
Missed prior year filings and need to catch up

Consequences of DIY when complex:

Errors leading to additional tax and penalties
Missing tax-saving opportunities
Wasted time (hours spent vs. accountant fee)
Stress and uncertainty

How to decide:

Calculate potential tax savings from professional optimisation
Compare with accountant fees
Consider peace of mind and time saved
Assess your own tax knowledge honestly

Our tax filing service handles complex situations with expertise, ensuring compliance whilst maximising legitimate deductions.

Mistake 12: Assuming ECI and Form C-S are the Same

The error: Filing ECI and thinking tax filing is complete, or vice versa.

Why it happens:

Confusing two separate filing requirements
Not understanding ECI is an estimate, Form C-S is final

The difference:

ECI (Estimated Chargeable Income):

Filed within 3 months of FYE
Estimate of taxable profit
Brief form, minimal detail
Exemption applies if revenue ≤ $5M AND ECI is nil

Form C-S / Form C:

Filed by 30 November of YA year
Final tax return with full details
No exemption (all companies must file)
Basis for tax assessment

Consequences:

Missing ECI: $200 penalty (even if exempt from filing Form C-S... wait, that's not possible)
Missing Form C-S: $200+ penalty, estimated assessment

How to avoid:

Treat them as separate obligations
ECI is first (3 months after FYE)
Form C-S comes later (30 Nov)
File both unless specifically exempt from ECI

Mistake 13: Not Reviewing Before Submitting

The error: Clicking "Submit" without thoroughly checking entered information.

Why it happens:

Rushing to meet deadline
Assuming system catches all errors
Fatigue after long data entry session

Common errors caught during review:

Typos in key figures (revenue, profit)
Wrong year selected
Forgot to enter unutilised amounts
Wrong exemption scheme
Missed mandatory questions

How to avoid:

Take 10-minute break before final review
Print or view summary before submitting
Check estimated tax payable makes sense
Verify key figures against financial statements
Use the filing checklist in Step-by-Step Filing Process

Tip: Review when fresh, not after spending 2 hours entering data. Your brain will spot errors better after a short break.

General Best Practices to Avoid Mistakes

1. Start early

Don't wait until November to begin
Finalise accounts by September
Allow time for queries and corrections

2. Keep organised records throughout the year

Don't scramble at year-end
File documents as you go
Maintain asset register in real-time

3. Understand before claiming

If you don't understand a deduction, research it
Don't claim something just because competitor does
Read IRAS guides for complex areas

4. Use checklists

Pre-filing checklist (documents needed)
During-filing checklist (fields to verify)
Post-filing checklist (documents to retain)

5. Learn from prior years

Review prior NOA for IRAS adjustments
If IRAS disallowed something, don't claim it again
Note what worked well for next year

6. Don't ignore red flags

Estimated tax seems too low? Double-check computation
IRAS querying same item repeatedly? Seek professional advice
Frequent late filings? Fix underlying cause (poor planning, inadequate resources)

7. When in doubt, ask

IRAS helpline: 1800 356 8300
Professional tax advisor
Fellow business owners (with caution - their situation may differ)

Avoiding these common mistakes ensures smoother filing, accurate tax assessment, and peace of mind. If you're concerned about making errors or want expert review of your return before submission, our tax filing service provides thorough checking and professional filing for complete accuracy.

DIY vs Hiring a Tax Agent

Should you file your corporate tax return yourself or engage a professional? This section helps you make an informed decision based on your situation.

When DIY Makes Sense

Your situation:

First 2-3 years of operation with simple structure
Revenue under $100,000
Straightforward business (trading, retail, simple services)
No capital allowance, renovation, R&D or other deductions
No related party transactions
No foreign operations
You have the financial statements or accounts ready
Qualifying for Form C-S (Lite)
You have basic accounting knowledge
Time available to learn and file carefully

Advantages of DIY:

Save professional fees ($350-$2,000 depending on complexity and whether you have prepared the financial statements on your own)
Direct control over filing process
Better understanding of your tax obligations
Learn skills useful for future years

Requirements for successful DIY:

Well-organised financial records throughout the year
Basic understanding of accounting concepts
Ability to follow instructions carefully
Time to research unfamiliar areas
Willingness to read IRAS guides

Tip: If attempting DIY for the first time, start preparation at least 8 weeks before the deadline. This allows time for research, mistakes, and corrections.

Realistic time commitment:

Preparing tax computation: 10-25 hours (first time)
Completing online filing: 1-3 hours
Total: 10-25 hours for first-time DIY filers
Subsequent years: 5-10 hours once familiar
Excludes the time required to prepare the accounting records and financial statements which might be around 50 hours for the first year

When to Hire a Professional

You should engage a tax agent if:

Complexity indicators:

Revenue exceeds $1 million
Must file Form C (exceeds $5M or claiming excluded items)
The accounting records and financial statements are not available
Group structure with related party transactions
Foreign operations or foreign tax credits
Significant asset disposals during the year
Claiming specialised deductions (s14N renovation, Capital allowances, R&D, IP allowances)
Recent business restructuring or acquisition
Multiple revenue streams from different sources

Compliance history:

Missed prior year deadlines
Previous IRAS queries or adjustments
Past penalties for incorrect filing
Need to catch up on multiple years

Resource constraints:

No time to learn tax rules properly
Accounting records are messy or incomplete
No in-house accounting staff
Higher value use of your time running the business

Risk management:

Tax amount is significant (errors costly)
Want professional liability protection
Peace of mind worth the fee
Prefer expert review before submission

Tip: Calculate your hourly business rate. If you earn $50/hour from your business, spending 20 hours on DIY tax filing costs you $1,000 in opportunity cost—more than most professional fees.

What Tax Agents Actually Do

Core services:

1. Tax computation preparation

Review financial statements
Identify tax adjustments (add-backs, deductions)
Calculate capital allowances correctly
Optimise deductions within legal boundaries
Prepare detailed tax computation worksheet

2. Form completion and filing

Determine correct form (C-S Lite, C-S, or C)
Complete all required fields accurately
Navigate complex questions correctly
Submit via myTax Portal
Provide acknowledgement to you

3. Advisory during process

Explain tax implications of transactions
Recommend timing strategies (when to incur expenses)
Identify tax-saving opportunities you may have missed
Clarify confusing tax rules

4. IRAS liaison

Respond to IRAS queries on your behalf
Provide supporting documentation
Negotiate with IRAS if disputes arise
Handle objections if assessment incorrect

What's typically NOT included (unless specified):

Bookkeeping and financial statement preparation
GST filing (separate service)
Payroll processing
Business advisory beyond tax

Important: Verify scope of service before engaging. Some firms bundle tax filing with accounting, others charge separately.

Cost of Professional Tax Filing

Typical fee ranges in Singapore:

Company Profile	Estimated Fee Range
Micro company (revenue <$200K, Form C-S Lite)	$350 - $$800
Small company (revenue $200K-$1M, Form C-S)	$500 - $2,500
Medium company (revenue $1M-$5M, Form C-S)	$1,000 - $4,000
Larger company (revenue >$5M, Form C)	$3,500 - $8,000+

Factors affecting fees:

Complexity of business operations
Number of transactions
Quality of bookkeeping records (messy records = higher fees)
Specialised claims (R&D, group relief, etc.)
Whether accounts preparation included
Urgency (rush jobs cost more)
Firm's reputation and expertise

Package deals: Many firms offer bundled services:

Monthly bookkeeping + annual accounts + tax filing: $5,000 - $15,000/year
Annual accounts + tax filing only: $3,000 - $8,000/year
Tax filing only (accounts already prepared): $800 - $3,000

Tip: Get quotes from 3 firms to compare pricing and scope. Cheapest isn't always best—consider experience, responsiveness, and what's included.

Cost-Benefit Analysis

Example scenario:

Company profile:

Revenue: $800,000
Net profit: $120,000
Chargeable income after adjustments: $100,000
Tax payable (with SUTE): ~$4,250

DIY approach:

Cost: $0 (your time)
Time: 8 hours
Risk: Potential errors, missed deductions

Professional approach:

Cost: $1,800
Time: 1 hour (review and sign off)
Benefit: Professional review, optimisation

Break-even calculation:

If tax agent identifies just $10,000 in legitimate additional deductions you missed:

Tax saved: $10,000 × 17% = $1,700
Fee paid: $1,800
Net cost: $100

If they save $15,000 in deductions:

Tax saved: $2,550
Fee paid: $1,800
Net benefit: $750

Intangible benefits:

Peace of mind
Time saved
Professional liability protection
Expert IRAS liaison if queries arise

Questions to Ask When Engaging a Tax Agent

Before committing, clarify:

1. Scope of service

"What exactly is included in your fee?"
"Do you prepare financial statements or only tax computation and filing?"
"Will you respond to IRAS queries at no extra charge?"
"Is GST filing separate?"

2. Experience and expertise

"How many clients in my industry do you serve?"
"Are you familiar with specific situation, e.g., R&D claims?"
"Who will actually handle my filing?" (Partner or junior staff? Is the work outsourced? Is the staff certified)
"What qualifications does your team have?"

3. Process and timeline

"When do you need my documents?"
"How long does your process take?"
"Will I get to review before submission?"
"What happens if we miss the deadline?"

4. Communication

"Who is my main contact?"
"How quickly do you respond to queries?"
"Do you proactively identify tax-saving opportunities?"

5. Fees and billing

"Is the quoted fee fixed or estimated?"
"What could cause the fee to increase?"
"When is payment due?"
"Are there any additional charges I should expect?"

Red flags:

Unwilling to explain their process
Guarantees specific tax savings before reviewing your records
Extremely low fees (potential quality issues)
Poor communication during sales process
No clear engagement letter

Hybrid Approach: DIY with Professional Review

Middle ground option:

How it works:

You prepare financial statements and/or tax computation yourself
Engage accountant/tax agent for review only
Agent checks for errors and optimisation opportunities
You file based on their reviewed computation

Advantages:

Lower cost than full-service ($500-$1,000 for review only)
You learn the process
Still get professional oversight
Catches errors before submission

When this works well:

You have accounting knowledge but want validation
Straightforward business but want peace of mind
Building capability for future DIY
Budget-conscious but risk-aware

When this doesn't work:

Records are messy (agent still needs to do significant work)
Complex situations requiring deep expertise
Very tight timeline (not enough time for back-and-forth)

Making Your Decision

Ask yourself:

Time and capability:

[ ] Do I have 6-10 hours available for tax filing?
[ ] Am I comfortable reading and understanding tax guides?
[ ] Are my financial records well-organised?
[ ] Do I have basic accounting knowledge?

Complexity:

[ ] Is my business straightforward (single revenue stream, no related parties)?
[ ] Am I filing Form C-S (Lite) or simple Form C-S?
[ ] Do I understand all the deductions I'm claiming?
[ ] Have I had no major changes this year (restructuring, acquisition, etc.)?

Risk tolerance:

[ ] Am I comfortable with potential small errors?
[ ] Is the tax amount relatively small (mistakes aren't catastrophic)?
[ ] Can I handle IRAS queries myself if they arise?
[ ] Am I confident I'm not missing tax-saving opportunities?

If you answered "yes" to most questions in all three categories: DIY is feasible.

If you answered "no" to several questions: Consider professional help.

If you're uncertain: Start with professional service for Year 1, then decide if DIY is viable for subsequent years once you've seen the process.

Switching from DIY to Professional (or Vice Versa)

DIY → Professional:

When to switch:

Business complexity increased
Made errors in prior DIY filing
IRAS queries you couldn't handle confidently
Time constraints changed
Revenue/profit grew significantly

Transition tips:

Provide new agent with prior 2 years' returns
Explain any unusual items or ongoing situations
Share prior IRAS correspondence
Clarify any ongoing queries or objections

Professional → DIY:

When to switch:

Gained accounting knowledge
Hired in-house accountant
Business simplified
Cost-cutting necessary
Want more control

Transition tips:

Request handover meeting with outgoing agent
Get copies of tax computations from prior years
Understand any carry-forward items (unutilised allowances, losses)
Clarify any complex areas before fully taking over
Consider review-only service for first DIY year

Our Tax Filing Service

If you've decided professional help makes sense for your business, our tax filing service offers:

What's included:

Comprehensive review of financial statements
Detailed tax computation preparation
Identification of all legitimate deductions
Optimal capital allowance calculations
Complete Form C/C-S filing
Acknowledgement and documentation
Response to IRAS queries (included, not extra charge)

Our approach:

Fixed, transparent pricing from $1,460/year
No hidden fees or surprise charges
Fast response (within 24 hours)
Direct communication via WhatsApp
Year-round support, not just filing season

Pricing packages:

Tax filing only: From $350
Annual accounts + tax filing: From $1,460
Full accounting package (monthly bookkeeping + accounts + tax): From $7,660

Get a quote: Contact us via WhatsApp to discuss your specific needs and get accurate pricing.

Whether you choose DIY, professional service, or a hybrid approach, the key is making an informed decision based on your actual situation—not just cost considerations. The best choice balances accuracy, compliance, time efficiency, and peace of mind for your specific circumstances.

Frequently Asked Questions

This section answers the most common questions about corporate tax filing in Singapore.

Filing Requirements and Deadlines

Q: Do all Singapore companies need to file corporate tax returns?

A: Yes, ALL Singapore companies must file annual corporate tax returns, regardless of whether they made a profit or loss. This includes dormant companies with no business activity unless you successfully applied for waiver to file tax

Q: What's the deadline for filing corporate tax returns?

A: 30 November of the Year of Assessment. For example, if your Financial Year End is 31 December 2024, you must file by 30 November 2025.

Q: I missed the 30 November deadline. What should I do?

A: File immediately. IRAS imposes a minimum $200 penalty for late filing, but penalties increase with delays. Don't wait—file as soon as possible to minimise additional penalties.

Q: Can I get an extension to the filing deadline?

A: IRAS may grant extensions in specific circumstances (complex restructuring, missing documents, overseas directors), but you must apply BEFORE the original deadline. Extensions are not automatically granted.

Q: What's the difference between ECI and Form C-S filing?

A: ECI (Estimated Chargeable Income) is filed within 3 months of your Financial Year End and provides an estimate of your taxable profit. Form C-S is your final tax return filed by 30 November with complete details. Both are required unless you qualify for ECI exemption.

Tip: Use our deadline calculator or contact our tax filing service if you're unsure about your specific deadlines.

Tax Forms and Eligibility

Q: How do I know which form to file - C-S (Lite), C-S, or C?

A: It depends on your revenue and what you're claiming:

Form C-S (Lite): Revenue ≤ $200,000, not claiming group relief/foreign tax credit/carry-back/investment allowance
Form C-S: Revenue ≤ $5 million, not claiming the four excluded items above
Form C: Revenue > $5 million OR claiming any of the four excluded items

The myTax Portal asks qualifying questions to guide you to the correct form.

Q: My revenue is $180,000 but I want to claim capital allowances. Can I still use Form C-S (Lite)?

A: You can claim standard capital allowances with Form C-S (Lite). You cannot claim carry-back of capital allowances to prior years. If you only need current year capital allowances, Form C-S (Lite) works fine.

Q: Can I change which form I file from year to year?

A: Yes. The form you file depends on your current year's circumstances. If your revenue grew from $150,000 to $3 million, you'd switch from Form C-S (Lite) to Form C-S.

Q: I have a group structure. Can I file Form C-S?

A: Having a group structure doesn't automatically disqualify you from Form C-S. However, if you're claiming group relief (transferring losses between group companies), you must file Form C.

Tax Computation and Deductions

Q: What's the difference between accounting profit and chargeable income?

A: Accounting profit is from your Profit & Loss statement. Chargeable income is your taxable profit after tax adjustments:

Add back non-deductible expenses (entertainment, depreciation, fines)
Deduct capital allowances and approved donations
This gives chargeable income, which is taxed at 17%

Q: I spent $50,000 on office renovation. How do I claim this?

A: Renovation costs can qualify under s14N renovation and refurbishment expenses

Q: Can I deduct entertainment expenses for clients?

A: Yes provided that it is solely for business purposes and you are able to provide info such as who specifically you entertained.

Q: What's a balancing charge and when do I need to calculate it?

A: Balancing charge applies when you sell an asset for more than its written-down value (cost minus accumulated capital allowances claimed). It's the excess that gets added back to your taxable income. If you didn't dispose of any assets, this is typically $0.

Q: I have unutilised capital allowances from last year. Where do I find this figure?

A: Check your prior year's Notice of Assessment (NOA) or Form C-S acknowledgement. Look for "Unutilised Capital Allowances carried forward" in the final section. Enter this amount in Part B of your current year's return.

Q: Are directors' fees tax-deductible?

A: Yes, directors' fees are deductible if they're approved at the AGM and actually paid or properly accrued during the financial year. They must be for genuine services rendered to the company.

Tax Exemptions and Rates

Q: What's the difference between SUTE and PTE?

A: SUTE (Startup Tax Exemption) applies to qualifying companies in their first 3 Years of Assessment:

First $100,000: 75% exempt (effective rate 4.25%)
Next $100,000: 50% exempt (effective rate 8.5%)

PTE (Partial Tax Exemption) applies to all other companies:

First $10,000: 75% exempt
Next $190,000: 50% exempt

Q: How do I know if I qualify for SUTE?

A: All conditions must be met:

Singapore-incorporated company
Tax resident in Singapore
First 3 consecutive Years of Assessment
All shareholders are individuals (no corporate shareholders) throughout the basis period
Shareholding held beneficially

Q: I had corporate shareholders for 2 months during the year. Do I still qualify for SUTE?

A: No. ALL shareholders must be individuals throughout the ENTIRE basis period. Even brief corporate shareholding disqualifies you from SUTE for that year.

Q: Which Year of Assessment am I in?

A: Year of Assessment = Financial Year End year + 1. If incorporated 15 March 2022:

YA 1: 2023 (for FYE in calendar 2022)
YA 2: 2024 (for FYE in calendar 2023)
YA 3: 2025 (for FYE in calendar 2024)
YA 4+: Use PTE instead of SUTE

Payment and Assessment

Q: When do I pay my corporate tax?

A: Within 1 month of receiving your Notice of Assessment (NOA) from IRAS. The NOA is issued 1-3 months after you file your return and states the exact amount due and payment deadline.

Q: Can I pay corporate tax in instalments?

A: Yes. Set up a GIRO arrangement to spread payment over 12 months interest-free. Apply via myTax Portal before the tax becomes due to avoid late payment penalties.

Q: IRAS assessed higher tax than I calculated. What should I do?

A: Review the Notice of Assessment carefully to understand their adjustments. If you disagree, file a Notice of Objection within 30 days of the NOA date, clearly stating your reasons and providing supporting documents.

Q: I haven't received my NOA yet. Should I be concerned?

A: Processing time varies:

Simple returns: 1-2 months
Complex returns or first-time filings: 2-4 months
Returns selected for review: 3-6 months

Contact IRAS if it's been over 4 months with no communication.

Record Keeping and Documentation

Q: What documents do I need to keep and for how long?

A: Keep ALL supporting documents for 5 years from the Year of Assessment:

Financial statements and tax computations
Sales invoices and purchase receipts
Bank statements
Employment records
Asset purchase documentation
Loan and rental agreements

Q: Can I keep digital copies instead of physical documents?

A: Yes, digital storage is acceptable provided documents are clearly legible and properly organised. Many businesses scan or photograph receipts immediately and store in cloud platforms.

Q: IRAS is asking for documents from 3 years ago. Do I have to provide them?

A: Yes. IRAS can request supporting documents up to 5 years after the Year of Assessment. Failure to provide requested documents may result in IRAS disallowing related deductions and imposing penalties.

Common Scenarios

Q: My company is dormant with no income or expenses. Do I still need to file?

A: Yes. ALL Singapore companies must file annual tax returns. For dormant companies, you'll report $0 income and expenses, but filing is still mandatory. The same deadlines and penalties apply.

Q: I changed my Financial Year End during the year. How does this affect filing?

A: You'll need to prepare financial statements for both periods:

Short period to the old FYE
Full period to the new FYE

Indicate "multiple sets of accounts" when filing and provide details of both periods.

Q: Can I file an amended return if I made a mistake?

A: You cannot edit a submitted return. Options:

Wait for NOA and file objection with corrections
Contact IRAS immediately to explain the error
File amended return only if IRAS specifically authorises it

Most errors can be corrected through the objection process after receiving your NOA.

Q: I'm a foreigner with a Singapore company. Any special requirements?

A: Filing requirements are the same regardless of your nationality. However, ensure:

Company is tax resident in Singapore (management and control exercised here)
You have proper access to myTax Portal (CorpPass or authorised Singpass)
Consider appointing local company secretary for compliance

Q: What happens if I wind up my company mid-year?

A: You must file a final tax return for the period from your last FYE to the date of cessation. The filing deadline is earlier than normal - typically within 1 month of cessation. Contact IRAS immediately when winding up begins.

GST and Other Taxes

Q: Is GST filing the same as corporate tax filing?

A: No, these are completely separate:

Corporate tax: Annual filing based on profit/loss
GST: Quarterly filing based on sales/purchases (if GST-registered)

Different deadlines, different forms, different requirements.

Q: Do I need to register for GST?

A: GST registration is mandatory if your annual revenue exceeds $1 million. You may voluntarily register if revenue is lower. GST registration is separate from corporate tax filing.

Q: I'm GST-registered. Does this affect my corporate tax filing?

A: Ensure your corporate tax return uses GST-exclusive revenue figures (revenue without GST). GST collected is not income; GST paid is not a deductible expense for corporate tax purposes.

Professional Help and Services

Q: When should I hire a tax agent instead of filing myself?

A: Consider professional help if:

Revenue exceeds $1 million
Complex business structure or transactions
Foreign operations or related party transactions
Claiming specialised deductions (R&D, group relief)
Limited time or tax knowledge
Peace of mind is worth the professional fee

Q: What should I expect from a professional tax filing service?

A: Quality services should include:

Review of financial statements for tax adjustments
Preparation of detailed tax computation
Identification of all legitimate deductions
Accurate form completion and filing
Response to IRAS queries (usually included)
Clear explanation of the process and results

Q: How much does professional tax filing cost?

A: Fees typically range from $800-$3,000 for most SMEs, depending on complexity. Factors affecting cost include revenue size, business complexity, quality of your records, and what's included in the service package.

Tip: For professional, reliable tax filing with transparent pricing, contact our tax filing service. We handle everything from computation to submission, ensuring accuracy and compliance while you focus on your business.

Need More Help?

IRAS Resources:

IRAS Helpline: 1800 356 8300 (Mon-Fri 8am-5pm)
myTax Portal: https://mytax.iras.gov.sg
IRAS e-Tax Guides: Detailed guides for specific topics

Professional Support:

Tax Filing Service: For complete filing assistance
Accounting Services: For ongoing bookkeeping and financial statement preparation
Business Advisory: For tax planning and optimisation strategies

Additional Reading:

SME Deductible Expenses Guide: Detailed breakdown of allowable deductions
GST Registration Guide: When and how to register for GST

Corporate tax filing doesn't have to be overwhelming. Whether you choose to file yourself or engage professional help, the key is understanding your obligations and ensuring accurate, timely compliance.

Corporate Tax Filing Singapore: Complete Guide for SMEs [2025]

Table of Contents

Understanding Singapore Corporate Tax

Singapore's Corporate Tax Rate in Regional Context

Corporate Tax Rate and Exemptions

Year of Assessment (YA)

Chargeable Income

Tax Residency: Detailed Determination

Types of Tax Forms

Understanding the Three Tax Forms

Key Differences: What Information Each Form Requires

How to Determine Which Form to File

Real-World Examples

Common Confusion: Tax Form vs Audit Requirements

Estimated Chargeable Income (ECI)

Can You Change Forms Year to Year?

Summary: Quick Form Selection Guide

Corporate Tax Filing Deadlines

Key Deadline: 30 November

Estimated Chargeable Income (ECI) Deadline

Complete Tax Filing Timeline

Penalties for Late Filing

Extension of Filing Deadline

Payment Deadline

Monthly Instalment Plan (GIRO)

What Happens If You Miss a Deadline?

Dormant Companies: Do Deadlines Apply?

Summary: Critical Dates to Remember

What You Need Before Filing

Financial Statements

Tax Computation

Supporting Documents

Access to myTax Portal

Information Specific to Each Form Type

Capital Allowances Documentation

Special Situations: Additional Documentation

Checklist: Are You Ready to File?

How Long Does Filing Take?

What If You're Missing Documents?

Common Tax Deductions for SMEs

General Rule for Tax Deductibility

Staff Costs (Fully Deductible)

Rental Expenses

Utilities and Telecommunications

Professional and Consultancy Fees

Insurance Premiums

Repairs and Maintenance

Transportation and Motor Vehicle Expenses

Marketing and Advertising

Technology and Software

Office Supplies and Equipment

Bank Charges and Interest

Entertainment Expenses (Deductible)

Travel Expenses

Donations

Research & Development (R&D)

Renovation and Refurbishment (Section 14N)

Intellectual Property (IP) Rights

What You CANNOT Deduct

Strategic Deduction Planning

How Deductions Reduce Your Tax Bill

Need Help Identifying Deductions?

Step-by-Step Filing Process

Before You Start Filing

Accessing myTax Portal

Completing the Tax Return

Part A: Qualifying Conditions

Part B: Tax Adjustments

Part C: Information from Financial Statements

Review and Submit

What to Do After Submission

Common Filing Errors and How to Fix Them

What If You Made a Mistake After Submitting?

Filing Checklist

Common Mistakes to Avoid

Mistake 1: Missing the Filing Deadline

Mistake 2: Filing the Wrong Form

Mistake 3: Misclassifying Capital vs Revenue Expenses

Mistake 4: Incorrect Capital Allowance Calculations

Mistake 5: Claiming Non-Deductible Expenses