Singapore ECI Filing: Deadline, Waiver and How to File (2026)

ECI stands for Estimated Chargeable Income. It is your company's estimate of its taxable profits for a Year of Assessment, after deducting tax-allowable expenses. It is not your final tax return; it is an early estimate that lets IRAS issue an assessment and, where applicable, set up your instalment plan before the final return is due.

Your company must file ECI within 3 months from the end of its financial year, unless it qualifies for the ECI filing waiver or it falls into a category that is specifically not required to file. IRAS sends a notification before the end of your financial year reminding you of the obligation, but the responsibility to assess whether you must file sits with your company. The full rules are on the IRAS ECI filing page.

Companies that never need to file ECI

Separate from the waiver, some entities are never required to file ECI:

• Foreign ship owners or charterers whose local shipping agent has submitted or will submit the Shipping Return
• Foreign universities
• Designated unit trusts and approved CPF unit trusts under Section 35(14) of the Income Tax Act 1947
• Real estate investment trusts granted the tax treatment under Section 43(2) of the Income Tax Act 1947
• Cases specifically granted a waiver to furnish ECI by IRAS

If your company is not on this list, the next question is whether it qualifies for the filing waiver, which is where most founders get the logic wrong.

Your company does not need to file ECI for a Year of Assessment when both of the following are true: annual revenue is S$5 million or below for the financial year, and ECI is nil for that Year of Assessment. Both conditions must hold. A company with S$5 million revenue but S$100,000 of ECI still files, and a company with nil ECI but S$10 million revenue still files.

What "revenue" means here

Revenue refers to your company's main source of income from its principal activity. It excludes separate-source income such as interest, dividends, and rental that does not arise from your principal activity. For an investment holding company, revenue is its investment income, such as dividend and interest income. Getting this definition right matters, because the wrong figure can push you over or under the S$5 million line.

"ECI is nil" is measured before exemptions

When the waiver refers to ECI being nil, that is the ECI amount before deducting the exempt amount under the partial tax exemption scheme or the start-up tax exemption scheme. Do not net off your exemptions first and then declare nil; that is a different number.

Self-assess, and do not be misled by "Ready to File"

You are required to self-assess whether you qualify. There is no need to seek confirmation from IRAS or to inform IRAS that you are using the waiver. Your filing status on myTax Portal may still show "Ready to File" even when you qualify for the waiver; that status does not override the waiver, and you are not required to file if you meet both conditions.

Do not confuse this with the audit exemption threshold

The S$5 million revenue figure here is specific to the ECI filing waiver. It is not the same as the small company audit exemption, which uses a S$10 million revenue threshold among its criteria. They are separate tests for separate purposes; our Singapore small company audit exemption guide covers that one.

If you do need to file, the process runs through myTax Portal and is usually quick once your figures are ready.

Step 1, Check your filing notification and status

IRAS notifies you before your financial year end. Log into myTax Portal with Corppass to see your ECI filing status. Corppass enrolment can take additional time if your company is not yet set up or if your directors are foreign nationals without Singpass, so handle that ahead of the deadline.

Step 2, Compute your ECI

Estimate your chargeable income for the Year of Assessment after tax-allowable expenses. Declare the ECI figure before applying the partial tax exemption or start-up tax exemption; IRAS applies those automatically. If you want the methodology behind the computation, the IRAS Basic Guide to Corporate Income Tax walks through it.

Step 3, File through myTax Portal

Submit the ECI through myTax Portal. The submission itself is immediate; what follows is the Notice of Assessment from IRAS.

Step 4, Choose GIRO to unlock instalments

If you pay by GIRO, you can spread your tax across instalments instead of a single payment. The number of instalments depends on how early you file, which is set out in the next section. To benefit, your company must be Singapore-registered and on GIRO. If you would rather not manage ECI computation and filing in-house, you can compare Singapore accounting providers that handle ECI filing as part of their service.

A missed ECI deadline does not just delay things; it can trigger an estimated Notice of Assessment that you then have to deal with. The cleaner path is to file on time, but there is a defined route back if you are caught out.

If you qualified for the waiver but still received an estimated assessment

This happens occasionally. IRAS may raise an estimated assessment based on the information it has, even for a company that actually qualified for the filing waiver. If that is your situation, write to IRAS through myTax Mail before the payment due date to confirm that your annual revenue is S$5 million or below and that your ECI is nil for that Year of Assessment. IRAS will amend the assessment accordingly, and no enforcement action will be taken for non-payment of the estimated tax. The key is to act before the payment due date rather than ignoring the notice.

If managing these deadlines and notices is becoming a drain, see our Singapore accounting and bookkeeping comparison for providers that track the compliance calendar for you.

ECI is not the end of the corporate tax cycle. It feeds two things that matter for your final position: the CIT Rebate and your Form C filing.

The YA 2026 CIT Rebate

For Year of Assessment 2026, the CIT Rebate is 50% of corporate tax payable, capped at S$40,000. This was enhanced from the original Budget 2026 figure of 40% and a S$30,000 cap. The rebate is computed automatically in your tax assessment from the ECI, Form C, Form C-S, or Form C-S (Lite) you file, so there is no separate application. Active companies that employed at least one local employee in 2025 may also receive a cash grant on top of the rebate, even if they have no tax payable. The official parameters, including the current cash grant amount, are on the IRAS Corporate Income Tax Rebates page.

ECI comes before Form C

ECI is the early estimate. Your final corporate income tax return is the Form C, Form C-S, or Form C-S (Lite), which is due by 30 November every year. The 30 November deadline gives companies at least 11 months to file after closing their accounts. Choosing the right form and filing it correctly is its own task; our Singapore corporate tax filing guide covers Form C, C-S, and C-S (Lite) and how they sequence with ECI.

1. Reading the waiver as an either-or test. The waiver applies only when revenue is S$5 million or below AND ECI is nil. Meeting one condition is not enough.
2. Assuming the "Ready to File" status on myTax Portal means you must file. If you qualify for the waiver, that status does not override it and you need not file.
3. Declaring ECI net of exemptions. The ECI figure is measured before the partial tax exemption and the start-up tax exemption, which IRAS applies for you.
4. Filing late and losing instalments. The deadline is 3 months either way, but filing in month one rather than month three is the difference between 10 and 6 GIRO instalments.
5. Ignoring an estimated assessment when you actually qualified for the waiver. Write to IRAS through myTax Mail before the payment due date and the assessment is amended.
6. Confusing the S$5 million ECI waiver threshold with the S$10 million small company audit exemption threshold. They are separate tests.
7. Treating the CIT Rebate as something to enter manually. It is computed automatically from your filing; do not reduce your taxable income to claim it.