Estimated Chargeable Income (ECI) filing — Step-by-step walkthrough

Raffles Corporate Services works with a panel of corporate and employment law firms; this article is general information, not legal advice.

Estimated Chargeable Income (ECI) is a company's estimate of its taxable income for a financial year, filed with IRAS ahead of the full tax return. This walkthrough explains who must file ECI, the three-month deadline, the waiver conditions, and how ECI connects to instalment payments for the 2026 cycle.

What Estimated Chargeable Income is

Estimated Chargeable Income is an early estimate of a company's chargeable income for a given financial year, submitted to IRAS before the detailed Form C-S or Form C is filed. It lets IRAS raise an early assessment and gives the company the option to pay its tax in instalments.

The obligation derives from the Income Tax Act 1947, under which companies are required to furnish an estimate of chargeable income within the period determined by the Comptroller of Income Tax.

For corporate-secretarial and related context, see Complete Guide to Setting Up a Family Office in Singapore (2026). Our companion article Singapore Budget 2026: Tax Rebates and Business Support for SMEs covers a related angle.

Who must file and who is exempt

A company must file ECI within three months of its financial year end unless it qualifies for the waiver. The waiver applies where annual revenue is S$5 million or below for the financial year and the ECI before exempt amounts is nil. A company meeting both conditions need not file ECI.

Dormant companies and those that have been granted a waiver of the income tax return obligation are treated separately, but most active SMEs either file ECI or confirm they meet the waiver.

On the immigration and employment side, see What Happens to Your Singapore Employment Pass When You Change Jobs.

How to calculate the estimate

ECI is the company's estimated chargeable income after deducting tax-allowable expenses and capital allowances, but before deducting the partial tax exemption or the start-up tax exemption. The figure is reported as revenue plus the estimated chargeable income, so the revenue line must be stated even when claiming the exemption scheme.

Because it is an estimate, ECI does not need to match the final return precisely, but a materially understated ECI can lead to a revised assessment and affect the instalment plan.

The deadline, payment and instalments

ECI is filed electronically through myTax Portal within three months of the financial year end. Filing ECI early unlocks an instalment plan for the resulting tax: companies that e-file sooner are offered a greater number of monthly instalments via GIRO, easing cash flow.

A company with a 31 December 2025 financial year end therefore files ECI by 31 March 2026, with the full Form C-S or Form C following by 30 November 2026.

Cost, timeline and getting it right

ECI preparation is usually bundled into an accounting or tax retainer; standalone preparation for an SME typically costs S$150 to S$500. The estimate can be produced within a few days of management accounts being available, well inside the three-month window.

Prepare ECI from reliable management accounts rather than a rough guess – a disciplined estimate reduces the risk of a revised assessment later.

Common mistakes and gotchas

Companies often miss the three-month deadline, assume the waiver applies without checking both conditions, or deduct the tax exemption before reporting ECI. Each is a recurring source of IRAS follow-up.

Step-by-step: preparing and filing ECI

Begin with reliable management accounts for the financial year. ECI is an estimate, but a disciplined estimate built from real figures is far safer than a guess, because a materially understated ECI can trigger a revised assessment. Adjust accounting profit for non-deductible expenses and capital allowances to reach estimated chargeable income.

Confirm whether the waiver applies before doing the work: if annual revenue is S$5 million or below and ECI before exempt amounts is nil, no filing is needed. If either limb fails, the company must file within three months of the financial year end.

File through myTax Portal as early as practical. Earlier e-filing unlocks a longer GIRO instalment plan, which spreads the tax across more months and eases cash flow – a concrete reward for filing ahead of the deadline rather than at it.

Numbers that matter: deadlines and instalments

The key figures are the three-month filing window after financial year end, the S$5 million revenue limb of the waiver, and the instalment tiers that reward early e-filing with more monthly GIRO instalments. A 31 December 2025 year end means an ECI deadline of 31 March 2026, with the corporate tax return following by 30 November 2026.

Report revenue plus estimated chargeable income, and remember that the figure is stated before the partial or start-up tax exemption is applied – a frequent point of confusion that leads to under-reporting.

Related guides and where to go next

ECI is the first of three connected filings – ECI, then the corporate tax return, against a backdrop of SFRS financial statements – so planning them as one cycle avoids missed deadlines. The cross-references here point to the related accounting and tax resources across the group.

Where cash flow is tight, filing ECI early to maximise the instalment plan is a simple lever, and Raffles Corporate Services can help structure the timing.

Official sources and further reading

Always verify the current position against the primary sources: www.iras.gov.sg, www.asc.gov.sg, www.acra.gov.sg.

FAQs

When is ECI due?
Within three months of the company's financial year end, filed through myTax Portal.

Do I have to file ECI if my company is small?
Not if annual revenue is S$5 million or below and ECI before exempt amounts is nil; otherwise filing is required.

Does filing ECI early help?
Yes. Earlier e-filing unlocks a longer GIRO instalment plan for paying the tax.

Need help with this? Call, SMS or WhatsApp +65 8501 7133, or email [email protected]. Raffles Corporate Services works with a panel of corporate and employment law firms; this article is general information, not legal advice.