ECI Filing in Singapore: Estimated Chargeable Income Guide and Checker

By Lucas Seah, Founder of Excellence Singapore Group | Last Updated: October 2026

Estimated chargeable income (ECI) is your company’s estimate of its taxable profit for a Year of Assessment (YA), and IRAS expects it within 3 months of the financial year end. For most companies, ECI filing is waived only when revenue for the year is S$5 million or below and the ECI is nil. Filing early also spreads the tax: a Singapore-registered company on GIRO that e-files by the 26th of the first month after its year end pays in 10 monthly instalments, and the number falls to 8, then 6, then none. For a 31 December 2026 year end, that means 26 January 2027 for 10 instalments and 31 March 2027 as the deadline.

ECI filing checker: do you need to file, and by when?

Pick your financial year end, answer three questions and, if you like, add the date you plan to file. The results update as you choose.

Key Takeaways

• File ECI within 3 months of the financial year end: a 31 December 2026 year end files for YA 2027 by 31 March 2027.
• The waiver needs both tests: revenue of S$5 million or below and a nil ECI, measured before the partial or start-up tax exemption. You do not tell IRAS you qualify.
• E-file by the 26th of the first, second or third month after the year end for 10, 8 or 6 GIRO instalments. After that there are none, even if the deadline has not passed.
• A late ECI can bring an estimated Notice of Assessment (NOA), payable in full within 1 month, and it counts as a bad compliance record.
• ECI is only an estimate: Form C-S, Form C-S (Lite) or Form C still follows by 30 November, and IRAS refunds or collects the difference.

Do you need to file ECI?

Apart from the few entities listed below, every company files ECI unless it meets both conditions of the ECI filing waiver for that YA:

1. Revenue of S$5 million or below for the financial year. Exactly S$5 million qualifies.
2. A nil ECI. The test is applied before the partial tax exemption or the start-up tax exemption, so a company with even a small chargeable income has a positive ECI and files, however little tax is left after the exemption.

IRAS's own example for a 30 June year end makes the point: S$5 million of revenue with S$100,000 of ECI must file, S$10 million of revenue with a nil ECI must file, and only S$5 million of revenue with a nil ECI is waived. A company with revenue above S$5 million and a nil ECI files 0 in the 17% row.

What counts as revenue. IRAS means the company's main source of income. Separate income such as interest, dividends or rent that does not come from the principal activity is left out, and so is a gain on selling fixed assets. For an investment holding company the rule flips: its revenue is its investment income.

You assess this yourself. IRAS sends an ECI notification in the last month of the financial year, and myTax Portal may show the YA as Ready to File. A company that meets both conditions simply does not file, and it need not tell IRAS. One that does not meet them must file, even if no notification arrived. If IRAS raises an estimated assessment on a company that qualifies, write in through myTax Mail before the payment due date to confirm the revenue and the nil ECI, and IRAS amends it.

A few entities are not required to file ECI at all: foreign ship owners or charterers whose local agent files the Shipping Return, foreign universities, designated unit trusts and approved CPF unit trusts, REITs with the tax treatment under section 43(2) of the Income Tax Act 1947, and cases IRAS has specifically excused.

ECI filing deadline for each financial year end

The deadline is 3 months from the end of the financial year. IRAS's examples all run from the last day of one month to the last day of the third month after it: 31 March to 30 June, 31 July to 31 October, 30 September to 31 December, and 31 December to 31 March. The table applies that rule to month-end year ends from 31 October 2026 to 30 November 2027.

Swipe sideways to see the full table →

A 30 November 2027 year end runs to 29 February 2028, because 2028 is a leap year. A year end on any other day, such as 15 June, still has 3 months, but IRAS's examples do not show how to count them, so confirm the date with IRAS. Plan to file by the date itself even when it falls on a weekend: IRAS's own example shows 30 June 2024, a Sunday, as a due date. For the rest of the annual calendar, see our monthly compliance checklist.

How ECI instalments work

IRAS lets a company pay its estimated tax in up to 10 monthly GIRO instalments, but only if it is registered in Singapore and pays by GIRO. E-file by the 26th of the first month after the year end for 10, the second month for 8 and the third month for 6. After that there are none, and the full tax is due within 1 month of the NOA. That last step catches companies out: for a 31 December year end, filing on 27 to 31 March is on time, yet IRAS's example gives no instalments after 26 March.

Three details from IRAS's ECI page shape the plan: each monthly deduction must be at least S$50, the first instalment can be combined with the second depending on the filing date, and IRAS may vary the plan if you file a revised ECI.

When the first deduction happens. IRAS illustrates this for a company with a December year end that files in January and is granted 10 instalments on S$10,000 of tax:

Deductions fall on the 6th of each month, or the next working day if the 6th is a weekend or public holiday. If a deduction fails, IRAS tries again on the 20th; if that fails too, it cancels the GIRO plan and the balance becomes due immediately. Pay the balance through Pay Taxes, or re-activate GIRO through Apply/ Manage GIRO Plan in myTax Portal, to avoid penalties. For other filing dates, IRAS shows the deduction dates in myTax Portal (View GIRO Plan) once the plan is set up.

GIRO must be in place in time. Without a GIRO arrangement for corporate tax, IRAS asks you to sign up at least 3 weeks before filing, and the arrangement must be approved before the payment due date, 1 month from the NOA, or the company pays the full tax in that month. eGIRO through myTax Portal can be approved instantly for several banks; paper applications take up to 21 working days.

How to calculate ECI

ECI is the company's taxable profit after tax-allowable expenses. Start from the net profit before tax, take out separate-source income, add back expenses that are not deductible, deduct capital allowances, then add the separate-source income back net of its own expenses. Unutilised capital allowances, trade losses and donations brought forward from earlier years are deducted too, subject to IRAS's conditions; IRAS's example has none. IRAS's worked example for a small trading company (financial year 2024, YA 2025):

The ECI is S$5,645, entered in the 17% row with revenue of S$80,000. Three rules from IRAS keep the figure right:

• Leave out the exemptions and the rebate. Report the ECI before the partial tax exemption or the start-up exemption; IRAS applies them automatically. Tick the start-up box in the form if the company qualifies.
• Group relief and loss carry-back. If the company claims losses under either system, the ECI is the figure after those loss items but still before the exemptions. For foreign tax credit claims, IRAS gives a formula in its ECI examples.
• Property developers report ECI on the completed contracts method.

If the year's accounts are not final when the ECI is due, the estimate is built from management accounts, which IRAS also accepts for the revenue figure. Closing the books promptly gives a firmer estimate; our guide to preparing for your financial year end sets out the steps. To turn the ECI into a tax figure, use our corporate tax calculator; it applies the exemptions and the YA 2026 rebate, so for a YA 2027 estimate read its Tax at 17% line, before the rebate.

How to file ECI on myTax Portal

1. Get the Corppass role right. The person filing must be authorised as an Approver for Corporate Tax (Filing and Applications) and log in with Singpass and the company's UEN. A Preparer can only enter the figures and send them to an Approver. Setting up GIRO needs the separate Corporate Tax (Payment) role.
2. Open File ECI under Corporate Tax.
3. Check the financial year end shown. If it is wrong, file anyway, then update the year end with ACRA through BizFile+. IRAS takes its records from ACRA, updating them weekly.
4. Select the YA and tick the start-up exemption box if the company qualifies.
5. Enter the revenue. Management accounts are fine if the audited accounts are not ready, and if the audited revenue later differs but the ECI does not, you need not revise it.
6. Enter the ECI in the row for its tax rate, rounded to the nearest dollar, or 0 in the 17% row if it is zero. Leave the tax payable boxes empty.
7. Submit and keep the acknowledgement, which stays in myTax Portal. Once IRAS processes a positive ECI, the NOA appears there; a nil ECI gets no NOA.

Late or missed ECI: what happens

IRAS's ECI page sets out the consequences of filing late or not at all:

• An estimated NOA, based on the company's past income or other information IRAS holds. The tax is payable in full within 1 month, with no instalments, even while an objection is pending; any excess is refunded if the assessment is revised.
• An objection window of 2 months from the date of that NOA, through the Revise/ Object to Assessment digital service, giving the reasons for the late filing and the revised ECI. Our Notice of Assessment guide explains the four NOA types and when an objection is needed.
• No instalments. You can still file after the 3 months while IRAS has not issued an NOA for that YA, but the company pays in full.
• Late payment penalties. An unpaid assessment attracts a 5% penalty; if the tax is still unpaid 60 days after that, IRAS may add 1% for each completed month, up to a further 12% of the unpaid tax, and it can appoint the company's bank or tenant to collect. Our guide to IRAS penalty waivers covers when an appeal is considered.
• A bad compliance record. Late ECI filing is one of the records IRAS weighs when it sets penalties for errors found in an audit: two within two years make a bad compliance history, an aggravating factor. IRAS's voluntary disclosure programme is the route to reduced penalties for errors you find yourself.

If an estimated NOA has already arrived, we prepare the objection with the revised ECI and the reasons IRAS asks for. Fees are quoted after we review the notice.

Revising ECI, and how it differs from Form C-S, C-S (Lite) and C

An ECI can be revised after filing through the Revise/ Object to Assessment digital service, and IRAS may adjust the instalment plan to match. The ECI and the Form C-S, Form C-S (Lite) or Form C are separate filings:

When the Form C-S or Form C comes in, IRAS refunds any excess tax automatically if the chargeable income is lower than the ECI, and collects the difference within 1 month of the new NOA if it is higher. A large gap may prompt IRAS to ask for an explanation, and an ECI lower than the final return shows is one of the reasons IRAS gives for raising an estimated assessment. Companies covered by the ECI waiver still file by the 30 November corporate tax deadline.

The YA 2026 rebate, and YA 2027

For YA 2026, IRAS grants a corporate income tax rebate of 50% of the tax payable, capped at S$40,000, including a S$2,000 cash grant for active companies that made CPF contributions for at least one local employee (shareholder-directors excluded) in 2025. A company that received the cash grant gets 50% of its tax, capped at S$40,000, less the S$2,000 already paid, and no rebate if 50% of its tax is S$2,000 or less. IRAS computes the rebate automatically from the ECI or the return, so the ECI you declare leaves the rebate out. IRAS's rates page lists no rebate for YA 2027 as at October 2026, so a company estimating its YA 2027 tax (financial years ending in 2026) should not count on one.

Special cases

New companies. IRAS sends no ECI notification in the year of incorporation, but a company that closes its first accounts in that year must still file within 3 months of that first year end unless the waiver applies. In IRAS's example, a company incorporated on 15 July 2023 with a December year end files its YA 2024 ECI by 31 March 2024 if its first accounts end on 31 December 2023; if they run to 31 December 2024, it files the YA 2024 and YA 2025 ECIs together by 31 March 2025.

Dormant companies. A company IRAS has excused from filing its income tax return also need not file ECI. Without that waiver, a dormant company with no income has a nil ECI and revenue under S$5 million, so the ECI waiver covers it, but its income tax return is still due by 30 November. Our dormant company tax guide explains both waivers.

Investment holding companies. The same rules apply, with revenue measured as the investment income, so dividends and interest count towards the S$5 million limit. Our holding company guide covers the wider tax position.

Companies striking off. If a company applying to strike off has already filed its Form C-S or Form C, financial statements and tax computation for a YA, IRAS does not require an ECI for that YA.

A change of financial year end. A change that straddles two YAs means two tax computations and two ECIs. In IRAS's example, moving the year end from 31 December 2024 to 31 March 2025 means filing the YA 2025 ECI by 31 March 2025 and the YA 2026 ECI, for the three months to 31 March 2025, by 30 June 2025. The change itself is filed with ACRA.

Frequently Asked Questions

Do I need to file ECI if it is nil?

Only if revenue for the financial year is above S$5 million. With revenue of S$5 million or below and a nil ECI, the waiver applies: there is nothing to file and IRAS does not need to be told. Above S$5 million, file the ECI as 0 in the 17% row. Nil is tested before the partial and start-up exemptions, so any chargeable income at all means filing.

Is there a penalty for filing ECI late?

IRAS's ECI page does not list a late-filing fine for ECI. The consequences it lists are an estimated Notice of Assessment based on past income or other information, the full tax due within 1 month with no instalments, and late payment penalties if that bill is not paid on time. A late ECI also counts as a bad compliance record when IRAS weighs penalties for errors.

Can I still file ECI after the deadline?

Yes, as long as IRAS has not yet issued a Notice of Assessment for that Year of Assessment. The company then loses its instalments and pays the tax within 1 month of the assessment. If an estimated assessment arrives first, file an objection within 2 months of its date, giving the reasons for the late filing and the revised ECI.

How many ECI instalments can my company get?

Up to 10. A Singapore-registered company on GIRO gets 10 monthly instalments if it e-files by the 26th of the first month after its year end, 8 by the 26th of the second month and 6 by the 26th of the third. The plan is subject to a minimum deduction of S$50 a month. Companies without a GIRO arrangement approved before the tax is due, or that file after the third cut-off, pay in full.

Can I revise my ECI after filing?

Yes. File the revised figure through the Revise/ Object to Assessment digital service at mytax.iras.gov.sg, and IRAS may vary the instalment plan to match. It is worth doing when profit turns out well above the estimate: an ECI lower than the final return shows is one of the reasons IRAS gives for raising an estimated assessment, and a significant gap may lead IRAS to ask for an explanation.

Does a dormant company need to file ECI?

Not if IRAS has granted it a waiver to file Form C-S, Form C-S (Lite) or Form C: IRAS confirms such a company need not file the ECI either. A dormant company without that waiver meets the general ECI waiver, with no revenue and a nil ECI, but it still files the Form for Dormant Company by 30 November. A company with the waiver that restarts business or receives income must tell IRAS within 1 month.

What is the difference between ECI and Form C-S?

ECI is a single estimated figure, filed with the revenue within 3 months of the year end. Form C-S is the actual return, due by 30 November, for companies incorporated in Singapore with revenue of S$5 million or below, only 17% income and no claims such as group relief. Skipping the ECI under the waiver does not remove the Form C-S.

Let us file your ECI

Excellence Singapore Group is a tax adviser and corporate services firm. Our corporate tax team checks whether the waiver applies, prepares the ECI from your management accounts, files it on myTax Portal by the instalment cut-off you choose and then prepares the Form C-S or Form C. We file the ECI from S$150 before GST, or confirm that the waiver applies. If your books need work before the year end, our accounting service keeps them ready, and our guide to accounting fees in Singapore shows what drives the cost. To get started, talk to us.