Estimated Chargeable Income (ECI): Deadlines and Instalments

Estimated chargeable income (ECI) is a Singapore company's estimate of its taxable profit for a year of assessment, and IRAS wants it within 3 months of the financial year-end. For a company that closes its books on 31 December, the financial year 2026 figure (Year of Assessment 2027) is therefore due by 31 March 2027. Filing early pays: a company on GIRO that files by 26 January 2027 can spread the tax over 10 monthly instalments, against 6 if it waits until late March and none after that.

Companies with revenue of S$5 million or below and a nil ECI need not file. This guide, from IRAS pages read on 28 October 2026, is general information, not tax advice.

Does my company need to file ECI?

Yes, unless IRAS's waiver applies. A company skips ECI for a year of assessment only when:

1. its annual revenue for the financial year is S$5 million or below, and
2. its ECI is nil, measured before the partial tax exemption or the start-up exemption.

The second condition catches small, profitable firms. A hypothetical consultancy with S$380,000 of revenue and S$8,000 of estimated taxable profit must file, even though the partial exemption would leave only S$2,000 to tax. IRAS's own table covers the other cases: a company with S$10 million of revenue and a nil ECI still files, entering "0" at the 17% rate, while one with S$5 million and a nil ECI need not.

Revenue means the main source of income, excluding interest, dividends and rent that do not arise from the principal activity. You assess the waiver yourself, even if myTax Portal shows "Ready to File"; if an estimated assessment arrives anyway, write in through myTax Mail before the payment due date.

When is ECI due, and when should you file it?

The due date is 3 months after year-end, and the instalment cut-offs fall on the 26th of each of those three months. IRAS's example is a December year-end:

• Filed by 26 January: 10 instalments.
• Filed by 26 February: 8 instalments.
• Filed by 26 March: 6 instalments.
• Filed after 26 March: no instalments.

Applying the same table to other year-ends is our reading, not an IRAS example. On it, a September year-end company gets 8 instalments if it files by 26 November 2026 and 6 by 26 December, ahead of its 31 December due date; its 10-instalment window closed on 26 October.

Each monthly GIRO deduction must be at least S$50, and IRAS may vary the plan if you revise your ECI. IRAS asks a company with no GIRO arrangement for Corporate Income Tax to sign up at least 3 weeks before filing, and the plan exists only if GIRO is approved before the payment due date, 1 month after the Notice of Assessment (NOA).

IRAS sends its reminder in the last month of the financial year, so December year-end companies should see it in December 2026. A new company gets no reminder in its year of incorporation but, says IRAS's basic guide to Corporate Income Tax (last updated 20 October 2026), must still file within 3 months if it closes its first accounts that year, unless the waiver applies.

How is the ECI figure worked out?

ECI is a short tax computation. IRAS's example starts from net profit before tax, removes rental income, adds back depreciation, property tax on the rental unit and expenses on an S-plated car, deducts capital allowances, then adds the rent back net of its property tax: S$6,645 of profit becomes an ECI of S$5,645.

When you enter the figure:

• Before exemptions. Declare ECI before the partial or start-up exemption; IRAS computes those itself. Indicate in the filing service if the company qualifies for the start-up exemption.
• No rebate. The rates page says the chargeable income declared in ECI should not include the CIT Rebate; IRAS computes any rebate itself.
• Management accounts are fine for the revenue figure if audited accounts are not ready.

Tax is a flat 17%. The partial tax exemption covers 75% of the first S$10,000 and 50% of the next S$190,000, at most S$102,500. Qualifying new companies may get the larger start-up exemption instead for their first 3 consecutive years of assessment.

Only a Corppass "Approver" for Corporate Tax (Filing and Applications) can submit ECI on myTax Portal; a "Preparer" can enter the figure but not file it.

Worked example: a December year-end firm files in January (illustrative)

A fictional fit-out contractor in Tai Seng, run by Nadia and Wei Jie, closes its 2026 accounts on 31 December. Management accounts show revenue of S$1.4 million and estimated taxable profit of S$150,000 after adjustments and capital allowances. It is past its first 3 years of assessment.

• ECI to declare: S$150,000, before any exemption.
• Partial exemption IRAS applies: S$7,500 (75% of S$10,000) plus S$70,000 (50% of the next S$140,000), so S$77,500.
• Tax: 17% of S$72,500 is S$12,325. No YA 2027 rebate was listed on 28 October 2026.
• Filed on 15 January 2027: 10 instalments of about S$1,232.50, on IRAS's Example 2 from 6 February to 6 November.
• Filed on 23 January: still 10, but on IRAS's pattern the first two (about S$2,465) come out together on 6 March.
• Filed by 26 February or by 26 March: 8 instalments of about S$1,541, or 6 of about S$2,054.
• Filed after 26 March: all S$12,325 is due within 1 month of the NOA, and missing that date adds a 5% penalty of S$616.25.

The instalment amounts are our division; IRAS may round differently.

What if you file late, or your estimate turns out wrong?

Late or not at all. IRAS may raise an estimated NOA from past income or other information, payable in full within 1 month even if you object. Objections are due within 2 months and must give the reason for the late filing and a revised ECI. A late ECI can still be filed before an NOA is issued, but without instalments.

Late payment. IRAS's late payment page (last updated 10 August 2026) adds a 5% penalty on tax unpaid by the due date, then a further 1% may be added for each completed month the tax stays unpaid beyond 60 days after that penalty, up to 12% of the unpaid tax. A failed GIRO deduction cancels the plan and makes the balance due at once.

Wrong estimate. Revise ECI through the "Revise/ Object to Assessment" digital service. When the actual return is assessed, IRAS refunds any excess automatically; a shortfall is payable within 1 month of that NOA. Our Form C-S guide covers that second return.

A December year-end checklist

1. Early December 2026: confirm someone holds the Corppass Approver role and that IRAS shows the right year-end (if not, update ACRA through BizFile+ and file anyway).
2. By late December: set up GIRO for Corporate Income Tax if you have none, at least 3 weeks before you plan to file.
3. First half of January 2027: close December's books; our month-end close checklist gets management accounts out quickly.
4. Before filing: test the waiver. Revenue of S$5 million or below and a nil ECI means you stop here.
5. By 20 January: file to start deductions on 6 February; 26 January is the last day for 10 instalments.
6. Keep the workings with your tax records; see how long to keep business records.

Other dates in the same months are in the SME compliance calendar and the Operations hub.

Common questions