IRAS Estimated Assessment: What to Do When Your Company Gets an Estimated NOA
An IRAS estimated assessment is a tax bill IRAS raises when your company misses its Estimated Chargeable Income (ECI) or Form C-S/C filing, based on past income or other information it holds. The tax is payable within 1 month of the notice date even if you disagree. To have it revised, you must object within 2 months and give IRAS your actual figures.
This guide is for directors who have found an estimated Notice of Assessment (NOA) in myTax Portal, or who expect one because the YA 2026 filing deadline of 30 November 2026 is close. Amounts are in Singapore dollars, and the rules are as at November 2026.
The estimate is not a fine, but it starts two clocks, one for payment and one for your objection, and the return you did not file stays outstanding.
Key takeaways
- Pay within 1 month of the NOA date, even if you object, or a 5% late payment penalty applies.
- Object within 2 months through the Revise/ Object to Assessment digital service, or the estimate becomes final.
- An estimate for a missed Form C-S or C is revised only when IRAS receives the return, financial statements and tax computation; for a missed ECI, IRAS needs your reasons and a revised ECI.
- Paying does not file the return: IRAS can still offer a composition of up to $5,000 per offence or summon the company to court.
- IRAS's milestone for objections is a decision within 6 months of receiving complete information.
Table of Contents
- What Is an IRAS Estimated Assessment?
- Do You Have to Pay an Estimated Assessment?
- How Do You Object to an Estimated Assessment?
- Your First 7 Days After an Estimated NOA
- What Happens If You Ignore an IRAS Estimated Assessment?
- What Documents Do You Need to File Quickly?
- What If Your Company Is Dormant?
- Does IRAS Issue Estimated Assessments for GST?
- Common Mistakes With Estimated Assessments
- When Should You Get Professional Help?
- Frequently Asked Questions
- Official Sources
What Is an IRAS Estimated Assessment?
An estimated assessment is IRAS's own calculation of your company's tax, made because it does not have your figures. It usually follows one of two missed filings:
- ECI not filed within 3 months of the financial year end. No ECI is needed if revenue is $5 million or below and ECI is nil.
- Form C-S, C-S (Lite) or C not filed by 30 November.
IRAS can also raise one when the ECI you filed looks too low, or as an advance assessment.
IRAS bases the figure on your company's previous years' income or other information it holds, and it may assume your income has increased. The result can be well above your real tax, or below it. In effect, the burden moves to the company: the estimate stands unless you object with your actual figures within 2 months.
Estimated NOA vs Normal NOA
Each type of corporate NOA carries its own wording, so you can tell them apart. Only one estimated type needs action from you.
| Wording on the notice | What it means | Do you need to object? |
|---|---|---|
| "This is an estimated tax assessment based on the information given by you or your tax agent." | Based on the ECI you filed | No |
| "This is an estimated tax assessment as we have not received your estimate of chargeable income/ Form C/ Form C-S etc." | Raised by IRAS: filing not received, ECI too low, or advance assessment | Yes, within 2 months, if you disagree |
| "This is an estimated tax assessment based on the information given in your Form C/ Form C-S." | Return filed and under review | No |
| "This is your tax assessment." | Final assessment | Only if you disagree, within 2 months |
The rest of this guide deals with the second row.
Do You Have to Pay an Estimated Assessment?
Yes. Tax on an estimated NOA is due within 1 month of the date printed on the notice, whether or not you object. Count from that date, not the day you opened it. If the assessment is later revised, IRAS refunds the excess by GIRO or PayNow Corporate within 30 days of the credit arising.
Two points catch companies out:
- No standard instalments. An estimate raised because ECI was not filed must be paid in full within 1 month, and IRAS's standard GIRO instalments are not granted for back-year taxes.
- Hardship plans must be requested. If the company cannot pay, apply for a longer plan through the Apply/Manage GIRO Plan digital service on myTax Portal; plans are only available by GIRO. IRAS considers factors such as financial distress, slow collections or falling sales, may ask for documents, and tells you the outcome within 15 working days, so apply early. If a deduction fails, the plan is cancelled and the balance becomes payable immediately.
Our view as practitioners: pay first and argue second. Paying on time keeps the 5% penalty off, and any overpayment comes back after the revision.
Example (hypothetical): Company A, with a 31 December year end, did not file its YA 2025 Form C-S. IRAS issues an estimated NOA dated 18 November 2026 for $24,000. Company A must pay by 18 December 2026 and object by 18 January 2027. It pays, then files a return showing tax of $6,000, so once IRAS revises the assessment, the $18,000 excess is refunded.
How Do You Object to an Estimated Assessment?
How you object to an estimated assessment, and what IRAS needs before it will revise it, depends on which filing was missed.
When Form C-S or Form C Was Not Filed
- Confirm the notice. Check the Year of Assessment (YA), the NOA date and that the wording says IRAS has not received your filing.
- Pay the estimated tax within 1 month of the NOA date, or apply for a payment plan before then.
- Prepare the missing figures. Finalise the financial statements for the financial year behind that YA, then the tax computation and supporting schedules.
- Lodge the objection within 2 months of the NOA date through the Revise/ Object to Assessment digital service at mytax.iras.gov.sg, submitting the Corporate Income Tax Return (Form C-S, C-S (Lite) or C), financial statements and tax computation. Without them, IRAS will not revise the estimate.
- Answer IRAS's questions by the due date in any request, or within 2 months of the letter if none is given.
- Check the revised NOA and the refund of any excess tax paid.
When Only the ECI Was Not Filed
If the estimate covers a missed ECI and the return for that YA is not yet due, your objection must give the reasons for the late filing (or failure to file) and the revised ECI amount. You still file the return by 30 November, and IRAS's assessment based on that return then replaces the estimate. Our ECI filing guide explains how to arrive at a sensible ECI.
There is one exception to paying and objecting. If your company qualified for the ECI filing waiver (annual revenue of $5 million or below and nil ECI for that YA) but still received an estimated NOA, write to IRAS through myTax Mail before the payment due date to confirm both points. IRAS will then amend the assessment and take no enforcement action for the unpaid estimated tax.
What IRAS Does After You Object
The digital service gives an instant acknowledgement. IRAS's published milestone is a written decision within 6 months of receiving your last correspondence with complete information; for complex cases it tells you the expected time. While your return is under review you may receive the third notice type in the table above, which needs no objection.
From 1 July 2027, companies must use this digital service for all objections and revisions, unless IRAS allows another channel in a particular case or class of cases. The change is made by the Finance (Income Taxes) Act 2026, which Parliament passed on 6 October 2026.
If the 2 Months Have Already Passed
IRAS treats an assessment as final once 2 months pass without an objection, and its corporate tax pages do not describe a route for late objections. The overdue return still has to be filed, so file it, have the financial statements and tax computation ready, and write to IRAS through myTax Mail explaining why you could not object in time. A revision is not guaranteed, which is why the objection date is the one to protect.
Your First 7 Days After an Estimated NOA
The deadlines are workable only if you start straight away.
| When | What to do | Why it matters |
|---|---|---|
| Day 1 | In myTax Portal (via Corppass), open Notices/ Letters > Corporate Tax and note the YA, NOA date, amount and wording. | Both deadlines run from the NOA date. |
| Day 1 | Diarise the payment date (NOA date plus 1 month) and the objection date (plus 2 months). Check View Late Filing Fee/ Summons. | A composition offer or summons has its own due dates. |
| Day 2 | Check who has Corppass access for Corporate Tax (Filing and Applications) and Corporate Tax (Payment), and authorise your accountant if needed. | Only an Approver can submit Form C-S, and replacing one who has left takes time. |
| Days 2–3 | Pay in full, or apply for a payment plan. | The 5% penalty applies once the due date passes. |
| Days 3–5 | Gather the records for the financial year behind the YA and decide which form applies. | This decides your path below. |
| Days 6–7 | Start that path. | The 2-month objection window is the hard limit. |
Decision Table: Accounts Ready, No Accounts or Dormant
| Your situation | What to submit | Next step | Watch out for |
|---|---|---|---|
| Accounts for that year are finished | Return, financial statements and tax computation with the objection | Prepare the tax computation and object now | Filing the wrong form |
| No accounts yet | The same, once the books are done | Engage a backlog accountant, set a filing date well inside the 2 months, and pay the estimate meanwhile | IRAS grants no extension of time for a previous YA's return |
| Company was dormant all year | The outstanding return (usually the Form for Dormant Company), plus an objection explaining it had no business or income | File and object, then consider a waiver | Any income, even fixed deposit interest, means it is not dormant |
| Only the ECI was missed | Reasons for the late filing and the revised ECI | Object now | The return is still due by 30 November |
What Happens If You Ignore an IRAS Estimated Assessment?
Ignoring the notice leaves two problems, unpaid tax and an unfiled return, and IRAS pursues both.
| Problem | What IRAS can do | Amount or effect |
|---|---|---|
| Unpaid tax | Late payment penalty once the 1-month due date passes | 5% of the unpaid tax |
| Unpaid tax | Additional penalty if still unpaid 60 days after the 5% | 1% for each completed month, up to 12% of the unpaid tax |
| Unpaid tax | Appoint agents such as the company's bank, tenant or lawyer, and take legal action | Agents are released only after tax and penalties are paid in full |
| No objection | Estimate treated as final after 2 months | You owe IRAS's figure |
| Unfiled return | Offer to compound the offence | Up to $5,000 per offence |
| Unfiled return | Notice under section 65B(3) of the Income Tax Act 1947 requiring a director to provide information | Failing to comply: fine of up to $10,000, up to 12 months' jail, or both, per offence |
| Unfiled return | Notice to Attend Court/Summons to the company and/or its directors | Fine of up to $5,000 per offence on conviction |
| 2 or more years unfiled | Prosecution | On conviction, the court may order a penalty of twice the tax assessed plus the fine; the returns must still be filed |
Had Company A paid nothing, a 5% penalty of $1,200 would follow the due date, and up to a further $2,880 (12% of $24,000) could build up after that: as much as $4,080 on top of the $24,000.
Directors carry personal risk. IRAS says they remain responsible for filing and payment even if the company's agent fails to act, and not attending court can lead to further action, potentially a warrant of arrest against the director. In its guide to the 2025 corporate tax season, IRAS reported that since January 2025 it had issued over 4,500 Notices to Attend Court to companies that had not filed returns for YA 2024 and earlier. If a composition offer or late payment penalty has already arrived, our guide to IRAS penalty waiver requests explains when an appeal can succeed.
What Documents Do You Need to File Quickly?
Start with the right financial year. Companies are taxed on a preceding-year basis, so for a 31 December year end, YA 2025 covers the year ended 31 December 2024. For that year, your accountant will need:
- bank statements for every company account for the full year;
- sales invoices or platform reports, and purchase invoices and receipts;
- payroll and CPF records;
- loan, hire purchase and lease agreements, and invoices for assets bought;
- last year's financial statements and tax computation, if any;
- details of money moving between the company and its directors or shareholders.
For Form C-S and C-S (Lite), the financial statements and tax computation are normally kept rather than submitted, but an objection to an estimated assessment needs them. Form C also needs Form IRIN 301, a detailed profit and loss statement and any claim forms. Our Form C vs Form C-S guide explains which form your company qualifies for.
Where records are inadequate, IRAS may estimate revenue using its best judgement and disallow expense claims, so rebuild what you can from bank statements and supplier copies. If the accounts were never prepared, the ACRA annual return (due 7 months after the financial year end for a non-listed company) is probably late too, and the same accounts fix both. See how to catch up on overdue company filings.
What If Your Company Is Dormant?
For tax purposes, a company is dormant if it carried on no business and had no income for the whole basis period. Fixed deposit interest counts as income, so a company that earned any interest is not dormant for that YA.
A dormant company must still file by 30 November unless IRAS has granted a waiver. If it misses the deadline, IRAS can take the same late filing actions as for any other company, including an estimated assessment. The fix is usually quick:
- Check the company's status in myTax Portal under Update Corporate Profile/ Contact Details. "No Business Done" means a waiver is in place; "Active" means a return is due.
- File the outstanding return. For a dormant year this is usually the simplified Form for Dormant Company, which has two essential fields, takes about 5 minutes and does not require financial statements to be submitted.
- Object within 2 months, explaining that the company had no business and no income. If IRAS asks for accounts that a dormant relevant company was exempt from preparing under section 201A of the Companies Act 1967, say so.
If the company will stay dormant, apply for a waiver so this does not recur. The conditions include having filed all returns, financial statements and tax computations up to the date business ceased, no income from any investments, GST deregistration if it was registered, and no plan to restart business within 2 years; our guide to the dormant company tax filing waiver covers the application.
Does IRAS Issue Estimated Assessments for GST?
Yes. If a GST F5 or F8 return is missed, IRAS issues an estimated NOA based on any information it has and imposes a 5% late payment penalty on the estimated tax. A $200 late submission penalty applies immediately, plus $200 for every completed month the return is outstanding, up to $10,000 per return.
For GST, the fix is to file: IRAS revises the estimated tax and penalty once you declare your actual liability, but only if you file within 5 years of the end of the accounting period. Paying the estimate does not remove the duty to file, and repeated non-filing can lead to a summons.
Common Mistakes With Estimated Assessments
- Ignoring the notice. The estimate becomes final once the 2-month objection window passes, unpaid tax attracts penalties and recovery action, and the return is still overdue.
- Paying and assuming it is over. Payment settles the bill, not the filing, so the late filing offence stays open.
- Filing only the ECI. If the estimate was raised because Form C-S or C was missing, a late ECI will not revise it.
- Objecting without documents. No return and accounts means no revision, and IRAS's 6-month milestone runs only from complete information.
- Getting the dates wrong. Both deadlines run from the date on the NOA, and the tax is due within 1 month whatever happens to the objection.
- Fixing one year and ignoring the rest. Check other YAs, GST returns and ACRA filings at the same time.
When Should You Get Professional Help?
You may not need us. If the accounts for that year are finished, the company qualifies for Form C-S or C-S (Lite) and a director has Corppass Approver access, you can object and file through myTax Portal yourself.
Get help when there are no accounts, more than one year is outstanding, the company must file Form C, you have a composition offer, a section 65B(3) notice or a summons, or the company cannot pay the estimate.
Tax Filing SG is run by ex-Big 4 Singapore Chartered Accountants (ISCA members) who serve Singapore SMEs. See our tax services for the tax computation and return, and backlog accounting where the books need rebuilding. We quote once we have seen the notice and your records.
Frequently Asked Questions
How long does IRAS take to revise an estimated assessment?
IRAS gives no specific timeline for revising an estimated assessment. Its milestone for objections is a written decision within 6 months of receiving your last correspondence with complete information, and it tells you the expected time for complex cases. For a missed Form C-S or C, nothing is revised until IRAS has the return, financial statements and tax computation. Excess tax is refunded by GIRO or PayNow Corporate within 30 days of the credit arising.
Does paying the estimated tax mean I do not need to file?
No. Paying on time settles the estimated bill and avoids late payment penalties on it, but the return is still outstanding. IRAS can still offer to compound the late filing offence, send a section 65B(3) notice to a director or summon the company to court. Even after a conviction, the overdue returns must be filed.
Will IRAS take legal action if I do not file Form C-S?
It can. IRAS may first offer to compound the offence for up to $5,000 per offence. If the return or composition payment is not received by the due date, it may issue a Notice to Attend Court/Summons to the company and/or its directors. On conviction the fine is up to $5,000 per offence, and for 2 or more years of non-filing the court may also order a penalty of twice the tax assessed.
Can a dormant company get an estimated assessment?
Yes, it can. Unless IRAS has granted a filing waiver, a dormant company must file by 30 November, and missing the deadline exposes it to the same late filing actions as any other company. File the outstanding return for that year (usually the simplified Form for Dormant Company), object within 2 months of the notice date, and apply for a waiver if the company will stay dormant.
What if the estimate is lower than the tax we actually owe?
You still have to file. The final assessment follows your return, so the difference becomes payable, and IRAS can raise an additional assessment within its 4-year time limit, or at any time where fraud is involved. A low estimate also leaves the late filing offence open, so accepting it saves nothing.
Can the late payment penalty on an estimated assessment be waived?
Possibly. A company can appeal through the penalty waiver digital service on myTax Portal. IRAS considers the appeal only if the overdue tax was paid in full by the due date in the late payment penalty notice and no waiver was granted in the past 2 calendar years. The outcome is instant, and successful appeals show in the tax account within 3 working days.
Official Sources
- IRAS: Late filing or non-filing of Corporate Income Tax Returns
- IRAS: After filing Form C-S/ C-S (Lite)/ C (NOA types and objections)
- IRAS: Estimated Chargeable Income (ECI) filing
- IRAS: Late payment or non-payment of Corporate Income Tax
- IRAS: Experiencing difficulties in paying your tax
- IRAS: Dormant companies
- IRAS: Late filing or non-filing of GST returns (F5/F8)
- IRAS: Your guide to Corporate Income Tax season 2025 (enforcement figures)
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About Tax Filing SG — We are a Singapore accounting practice run by ex-Big 4 Singapore Chartered Accountants (ISCA). We handle accounting, corporate tax, GST and company secretarial work for Singapore SMEs, including overdue and late filings.
Last updated: 9 November 2026. This article is general information based on IRAS and ACRA guidance as at November 2026, not advice for your specific situation. Rules, rates and deadlines change, so check the official sources above or speak to us before acting.