Every company incorporated in Singapore must estimate its taxable income and report it to the Inland Revenue Authority of Singapore (IRAS) within 3 months of its financial year-end (FYE). This estimate is called Estimated Chargeable Income (ECI). All companies must e-File ECI within 3 months of their FYE unless they qualify for the filing waiver, per the IRAS ECI filing page-filing). Miss the deadline without a valid waiver and IRAS raises an estimated assessment you still have to pay.
The verdict on ECI filing and IRAS tax filing: file within 3 months of your FYE, unless your company meets both waiver conditions, annual revenue of S$5 million or below AND nil ECI for the Year of Assessment (YA). Get the waiver wrong and estimated assessments follow. This guide covers deadlines, the waiver, myTax Portal steps, GIRO installments, and penalties for corporate tax filing in Singapore.
What Is Estimated Chargeable Income (ECI) in Singapore?
ECI is a company’s estimate of its chargeable income for a Year of Assessment (YA), calculated after tax-allowable expenses but before exempt amounts such as the partial tax exemption or the Start-Up Tax Exemption. Chargeable income is not accounting profit; tax adjustments like add-backs of non-deductible expenses and capital allowances apply. IRAS uses ECI to raise an early assessment.
An ECI filing declares two figures, revenue and the ECI amount, and both are required. Revenue means the company’s main source of income and excludes items like gains on disposal of fixed assets, interest, dividends, and rental not arising from the principal activity, per IRAS. For an investment holding company, IRAS treats its investment income, such as dividend and interest income, as its revenue.
Who Must File ECI in Singapore?
All Singapore-incorporated companies must file ECI within 3 months of their FYE, unless waived or specifically excluded, per IRAS. Not receiving a filing notification does not remove the obligation. A short list of entity types is excluded from ECI filing entirely.
- Foreign ship owners or charterers whose local agent files the Shipping Return
- Foreign universities
- Designated unit trusts and approved Central Provident Fund (CPF) unit trusts
- Real Estate Investment Trusts (REITs) granted tax treatment under Section 43(2) of the Income Tax Act 1947
- Cases specifically granted an ECI waiver by IRAS
Source: IRAS ECI filing page.
Who Qualifies for the ECI Filing Waiver?
A company qualifies for the ECI filing waiver only if it meets both conditions: annual revenue of S$5 million or below for the financial year, AND nil ECI for the YA, computed before exempt amounts, per IRAS. Meeting only one condition does not exempt you. The waiver is self-assessed, so you need not notify IRAS even if myTax Portal still shows “Ready to File.”
The two conditions are cumulative. A company with S$4 million revenue but positive ECI still files. A company with nil ECI but S$6 million revenue still files. IRAS raised this revenue threshold from S$1 million to S$5 million effective YA 2017 to reduce compliance costs, per IRAS. If a waiver-qualifying company still receives a Notice of Assessment (NOA), it must confirm via myTax Mail before the payment due date, and IRAS then amends the assessment with no enforcement action.
When Is the ECI Filing Deadline?
File ECI within 3 months of your FYE, per IRAS. A 31 December year-end means a 31 March deadline the following year. IRAS sends a filing notification in the last month of your FYE, but only from the year after incorporation, and the absence of a notification does not remove the deadline.
| Financial year-end (FYE) | ECI filing deadline | Source |
|---|---|---|
| 31 January | 30 April | IRAS |
| 31 March | 30 June | IRAS |
| 30 June | 30 September | IRAS |
| 30 September | 31 December | IRAS |
| 31 December | 31 March (following year) | IRAS |
IRAS’s own worked example confirms a 30 June 2024 FYE (YA 2025) files ECI by 30 September 2024, per IRAS. If the FYE shown on myTax Portal is wrong, you can still file, and you should update your FYE with the Accounting and Corporate Regulatory Authority (ACRA) and IRAS.
Do Newly Incorporated Companies Need to File ECI?
Yes. A newly incorporated company files ECI within 3 months of its first FYE unless it meets both waiver conditions. IRAS generally sends no ECI notification in the year of incorporation; notifications start from the year after, per IRAS. The obligation applies whether or not a notification arrives.
If the first accounting period exceeds 12 months, IRAS splits it across two YAs, so you estimate and file ECI for each YA separately. ECI is declared before exemptions. A new company with S$100,000 of chargeable income declares S$100,000 as its ECI; IRAS then applies the Start-Up Tax Exemption (SUTE) when computing the tax assessed. See the corporate tax rates in Singapore for how exemptions reduce the final bill.
What Is a Nil ECI Filing and When Is It Required?
A nil ECI filing declares your ECI as “0”. A company with zero chargeable income that fails either waiver condition, for example revenue above S$5 million, must still file a nil ECI on myTax Portal, per IRAS. A nil ECI produces no Notice of Assessment.
A nil ECI differs from dormant-company status. A dormant company can apply to IRAS for a waiver of its Corporate Income Tax return, and the waiver is not automatic. Once granted, it need not file ECI or Form C, but the company must notify IRAS and resume filing when it recommences business or starts receiving income, per IRAS dormant-company guidance.
How Do You File ECI on myTax Portal? (Step-by-Step)
File ECI in five steps: log in, confirm Corppass access, open File ECI, declare revenue and ECI, then submit and save the acknowledgment. You log in with Singpass, and your Corppass authorization grants access to the company’s tax matters, per IRAS.
- Log in to myTax Portal with your Singpass.
- Confirm Corppass authorization. The filer needs the right Corporate Tax role, typically a Preparer role to draft and an Approver role to submit; check current role names on Corppass.
- Go to Corporate Tax > File ECI.
- Declare your revenue and ECI figures, both required, and indicate any tax exemption scheme claimed.
- Review, submit, and save the acknowledgment page.
Non-resident companies without a local presence in Singapore may need a local filing agent to file on their behalf.
What Documents Do You Need for ECI Filing?
You need six things to file ECI: Singpass login, Corppass authorization, your company’s Unique Entity Number (UEN), financial statements or management accounts, your revenue figure, and a tax computation supporting the ECI amount. ECI is an estimate, so a reasonable computation basis is expected rather than final audited accounts.
- Singpass login and Corppass authorization
- Company Unique Entity Number (UEN)
- Financial statements or management accounts
- Revenue figure (main source of income)
- Tax computation supporting the ECI (add-backs, capital allowances)
- Details of any tax exemptions claimed
How Do GIRO Installments Work After Filing ECI?
Filing ECI early and being on GIRO, Singapore’s interbank recurring payment scheme, unlocks interest-free monthly installments, and the earlier you e-File, the more installments IRAS grants. e-File within one month of your FYE for 10 installments, within two months for 8, and within three months for 6, per IRAS. File after three months and you lose installments.
| ECI e-Filing window (from FYE) | Installments (e-File) | Installments (paper) | Source |
|---|---|---|---|
| Within 1 month | 10 | 5 | IRAS |
| Within 2 months | 8 | 4 | IRAS |
| Within 3 months | 6 | 3 | IRAS |
| After 3 months | None | None | IRAS |
IRAS ties these tiers to e-Filing by the 26th of the first, second, or third month after your FYE, and each installment has a minimum deduction of S$50, per the IRAS GIRO for Corporate Income Tax page. Two conditions apply: on-time filing within the qualifying window and active GIRO enrollment. Late filers pay in one lump sum.
What Happens If You File ECI Late or Not at All?
If a company required to file misses the 3-month deadline, IRAS issues an estimated Notice of Assessment (NOA) based on its own estimate of your income, and you must pay it within 1 month even if you disagree, per IRAS. Failure to file is an offence under the Income Tax Act 1947.
| Consequence | Detail | Source |
|---|---|---|
| Estimated NOA | Payable within 1 month, no installment option | IRAS |
| Composition fee | Up to S$5,000 for late or non-filing | IRAS |
| Late payment penalty | 5% on unpaid tax, plus a further 1% per completed month after 60 days, capped at 12% | IRAS |
| Non-filing 2+ years | Up to twice the tax assessed plus a fine up to S$5,000 on conviction | IRAS |
You can object to an estimated NOA within 2 months of the NOA date, stating your grounds for late or non-filing and a revised ECI figure, per IRAS. You must still pay the assessed amount within 1 month, and IRAS refunds any excess if your objection succeeds. Late filing remains possible if no NOA has been issued for the YA, but you lose installment eligibility. See the IRAS late payment penalties page for the payment penalty schedule.
How Do You Pay Tax After the ECI Notice of Assessment?
After IRAS processes your ECI, the Notice of Assessment (NOA) appears on myTax Portal and payment is due within 1 month of the NOA date, unless you qualify for GIRO installments, per IRAS. A nil ECI generates no NOA, so there is nothing to pay.
Two payment routes are available: GIRO for interest-free monthly installments, and electronic payment by internet banking, phone banking, or NETS. See the IRAS paying corporate income taxes page for the full list of payment modes.
What Is the Difference Between ECI and Form C-S or Form C?
ECI is the early estimate filed within 3 months of your FYE. Form C-S, Form C-S (Lite), or Form C is the final Corporate Income Tax return, filed by 30 November of the YA with actual figures, per IRAS. IRAS reconciles the two, and filing ECI does not replace the annual return.
| ECI | Form C-S / Form C-S (Lite) / Form C | |
|---|---|---|
| Purpose | Estimate of chargeable income | Final Corporate Income Tax return |
| Deadline | Within 3 months of FYE | By 30 November of the YA |
| Figures | Estimate, before exempt amounts | Actual figures, full tax computation |
| Outcome | Early assessment and GIRO installments | Definitive tax liability |
| Source | IRAS | IRAS |
Form C-S is for companies with revenue of S$5 million or below meeting the conditions, Form C-S (Lite) is for revenue of S$200,000 or below, and Form C covers the rest. For YA 2026, the Form C-S and Form C deadline is 30 November 2026, per the IRAS Corporate Income Tax filing season 2026 page.
How Commenda Helps With ECI Filing in Singapore
Commenda’s corporate tax and bookkeeping service tracks your ECI deadline off your FYE, prepares the tax computation, and files with IRAS so your estimate and final Form C-S reconcile. It handles ECI alongside your other IRAS obligations, including GST filing in Singapore and withholding tax obligations, on one compliance calendar.
Commenda connects to your accounting data through 100+ ERP, API, and custom integrations and maps every deadline in the compliance calendar. See how ECI fits your wider statutory compliance in Singapore. Book a demo to get your Singapore filing calendar mapped, ECI through Form C-S.
