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Answers · Corporate income tax · ECI · due 3 months after the year end

When is my ECI due, and do I have to file it at all?

Your ECI (Estimated Chargeable Income) is due within 3 months after your financial year end, so a year ending 31 Dec 2025 is due by 31 Mar 2026. You do not have to file it when both of these hold: revenue for the financial year of S$5,000,000 or below, and a nil ECI.

One condition alone is not enough. A loss-making company with revenue above the cap files; a profitable company under the cap files.

Computed from the rulebook Edition YA-2027 · sources verified through 24 Jul 2026

Your due date, by financial year end

IRAS publishes the ECI deadline as a table keyed on the month your financial year ends in, and every row is the last day of the third month after it. The table below is that arithmetic, computed for the twelve most recent month ends.

Financial year endedECI due by
30 Sep 202531 Dec 2025
31 Oct 202531 Jan 2026
30 Nov 202528 Feb 2026
31 Dec 202531 Mar 2026
31 Jan 202630 Apr 2026
28 Feb 202631 May 2026
31 Mar 202630 Jun 2026
30 Apr 202631 Jul 2026
31 May 202631 Aug 2026
30 Jun 202630 Sep 2026
31 Jul 202631 Oct 2026
31 Aug 202630 Nov 2026

A year that ends mid-month is outside IRAS's table and takes the plain reading: the same day of the month 3 months on. Simpler Tax's engine uses the same rule, so its year map shows the date above for your own year end.

The waiver: both conditions, not either

You are not required to file an ECI when, for the financial year, revenue is S$5,000,000 or below and the ECI is nil. Revenue means the income from the company's principal activity, and leaves out interest, dividends and rent earned on the side; for an investment holding company that investment income is its revenue. The ECI tested is the chargeable income before the exempt amount, so a company that would owe nothing only because of the partial tax exemption still has a positive ECI and still files.

Nothing is sent to IRAS to claim the waiver. You assess it, and if it applies you do nothing; myTax Portal may still list the ECI as ready to file, and that is not a demand.

Worked

Three companies, one test

CompanyRevenueECIRevenue testNil testVerdict
Company Aa small trading company that made a lossS$300,000.00nilmetmetWaived: nothing to file
Company Bthe same size, with a profitS$300,000.00S$20,000.00metnot metFiles the ECI
Company Ca large company with a nil yearS$6,000,000.00nilnot metmetFiles the ECI

Company A files nothing. Company B files its ECI of S$20,000.00 within 3 months of its year end. Company C has no tax to estimate and still files, because its revenue is over the cap; its ECI is nil.

Filing early buys more instalments

If the company pays by GIRO, the number of monthly instalments IRAS allows depends on how soon after the year end the ECI is filed. Deductions are made on the 6th of each month.

ECI e-filedInstalments
By the 26th of month 1 after the year endUp to 10
By the 26th of month 2 after the year endUp to 8
By the 26th of month 3 after the year endUp to 6
After the 26th of the third monthNone: the tax is paid in one sum

Without GIRO, the whole amount on the notice of assessment is due within 30 days of the notice.

What the ECI is, and what it is not

An early estimate of the profit you will be taxed on, filed within three months of your financial year end, long before the real return. It estimates the chargeable income before the exempt amount, the same figure that becomes item 20 of Form C-S when the return is filed by 30 November of the year of assessment. IRAS assesses on the estimate and applies the exemption itself; when the return arrives, the assessment is revised to the actual figure.

The ECI is not the profit in your accounts. It is that profit after the tax adjustments: non-deductible expenses added back, capital allowances taken, separate-source income handled on its own lines. See the Form C-S items, line by line.

Do it in Simpler Tax

The ECI pack tests both conditions from your ledger

Simpler Tax reads revenue from the posted books and computes the ECI on the same chain as the Form C-S, then tests the waiver: it says either "nothing to file" with the arithmetic that proves it, or the figure to type into myTax Portal. The due date for your own year end sits on the year map. Simpler Tax files nothing.

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Questions people ask

My financial year ends on 30 June. When is my ECI due?

30 Sep 2026 for the year that ended 30 Jun 2026: the last day of the third month after the year end. A 31 December year end is due by 31 Mar 2026, and a 28 February one by 31 May 2026.

Is the ECI waiver automatic, or do I apply for it?

You assess it yourself and file nothing. If revenue is S$5,000,000 or below and the ECI is nil, there is nothing to send; myTax Portal may still show the ECI as ready to file, which does not change the answer.

Does a new company file an ECI in its first year?

Yes, within 3 months of its first financial year end, unless both waiver conditions hold for that first year.

Is the ECI the same figure as the one on Form C-S?

It is an estimate of the same figure: the chargeable income before the exempt amount, item 20 on Form C-S. The final figure goes on the return by 30 November of the year of assessment; the ECI comes first so that IRAS can assess and you can start paying by instalments.

What does revenue mean for the S$5 million test?

The income from the company's principal activity: sales, fees, the trade itself. Interest, dividends and rent earned on the side are left out, unless the company is an investment holding company, in which case that income is its revenue.

What happens if I do not file the ECI?

IRAS may raise an estimated assessment of its own, and that estimate is payable whether or not it is right. The tax on a notice of assessment is due 30 days after the notice, with 5% added if it is late.

Sources

Statutory figures on this page are read from the Simpler Tax rulebook at build time, edition YA-2027, every source last checked 24 Jul 2026. The rulebook entries named below are the ones this page was computed from; the IRAS pages are what they were verified against.