Corporate tax filing
done right the first time.
Form C · Form C-S · Form C-S (Lite) · ECI
Every Singapore-incorporated company files two things a year: an Estimated Chargeable Income within 3 months of financial year-end, and a full tax return by 30 November. We prepare the computation, pick the right form, and e-file both.
Tax Computation · YA2026
- Tax rate: 17% flat
- ECI window: 3 months from FYE
- Form C-S revenue cap: $5,000,000
- Form C-S (Lite) cap: $200,000
- Filing deadline: 30 Nov
- Late filing risk: Est. NOA + court risk
- 2 Filings a year
- 3 Form types
- 7pg Form C length
- 3pg Form C-S length
- 6 Fields, C-S (Lite)
Overview
Two filings, one Year of Assessment
Estimated Chargeable Income (ECI)
- Annual revenue of $5 million or below for the YA, and
- ECI is nil for that financial year (before deducting any tax exemptions the company enjoys)
- Tax rebate — Up to 20% off, capped at $10,000. Filing ECI qualifies the company for a Corporate Income Tax rebate, sized to total taxable income and capped regardless of company size.
- Instalment payment — Up to 10 instalments. E-file in month 1 after FYE for up to 10 instalments; month 2 drops to 8; month 3 to 6. Paper filing gets roughly half as many instalments at each stage. Filing after month 3 forfeits installment eligibility.
Which form applies to your company
Condition | Form C-S (Lite) | Form C-S | Form C |
Annual revenue | $200,000 or below | $5 million or below | Any company |
Length | 6 essential fields | 3 pages, 18 fields | Full 7-page form |
Financial statements submitted | Not required | Not required | Required |
Income taxed only at prevailing 17% rate | Required | Required | Not required |
Claiming Group Relief, loss carry-back, investment allowance or foreign tax credit | Not allowed | Not allowed | Allowed |
Good to know: companies that qualify for Form C-S (Lite) can still choose to file Form C-S or Form C instead — the simplified form is an option, not an obligation.
- (Form C only) Financial statements — Audited or unaudited, unless a complete XBRL set was filed with ACRA, or the company was dormant for the YA.
- (Form C only) Profit & loss statement — A detailed P&L account covering the Year of Assessment in question.
- (All forms) Tax computation — Your company’s computation for the YA, with supporting schedules — required for Form C, Form C-S and, where relevant, Form C-S (Lite).
- (Older companies) Revised tax computation — IRAS may request tax computations for all prior YAs alongside the current filing.
- (If applicable) Claim forms — For companies claiming R&D expenditure relief or Group Relief.
- (If applicable) Declaration form — Required for Writing Down Allowance claims, e.g. on intellectual property, and for Form C-S declarations confirming eligibility.
- Get CorpPass authorisation — The person filing must be authorised by the company as an “Approver” for corporate tax matters in CorpPass. Set this up before the filing window opens.
- Gather your reference numbers — Have your company’s UEN and CorpPass login on hand, along with accounting records converted to PDF — all supporting documents must be submitted in PDF format.
- Log in to the IRAS tax portal — Visit mytax.iras.gov.sg, select Business Tax, and log in via CorpPass. Enter your company’s UEN when prompted.
- Select Corporate Tax, then your form — Choose Form C, Form C-S or Form C-S (Lite) as applicable, and select the correct Year of Assessment.
- Complete and submit — You can save progress and resume later within the filing window. Form C-S typically takes 10–15 minutes to complete online. The portal auto-logs-out after roughly 20 minutes of inactivity.
- Estimated Notice of Assessment (NOA) — IRAS estimates your tax bill from prior filings and available information. Payment is due within 1 month of the NOA.
- Notice of Objection (NOO) — You can object within 2 months of the NOA — but the estimated amount must still be paid first. Any excess is refunded if the objection succeeds.
- Composition fee — A fee of $200 – $1,000 may be imposed for continued non-compliance, in addition to the outstanding NOA.
- Section 65B(3) notice — IRAS can compel your company director directly to submit the required Form C-S/C information.
- Court summons — Directors found guilty face a fine of up to $10,000, a 12-month jail term, or both.
| Service | Fee |
|---|---|
| Waiver of Form C for dormant companies | $200 |
| Small Business (Revenue < SGD 5 million) | From SGD 500 |
| Large Business (Revenue > SGD 5 million) | From SGD 1,000 |
| Sole proprietorship / partnership tax filing | $300 – $400 |
| Other ad-hoc tax services (e.g. personal income tax) | From $300 |
| Capital allowance / S14N R&R claims (add-on) | +$50 – $150 |
Note: Actual fee for corporate tax filing is dependent on the number and complexity of tax adjustments required.
Why HeySara
Tax filing that doesn't rely on you remembering a date
ACRA-registered agents
Deadline reminders, not surprises
One team, full picture
Straightforward pricing
Not sure which form applies?
Send us your last financial year’s revenue and we’ll tell you exactly which form to file and what it’ll cost.
FAQs
Yes. Qualifying for the simplified form is optional, not compulsory — some companies prefer the fuller Form C-S or Form C for their own record-keeping.
For the current YA, a request can be made online via IRAS’s “Request Penalty Waiver / Extension of Time to File” service — but not once a Court summons has been issued. For overdue prior-year returns, no extensions are granted at all.
Your company’s taxable income for the YA, after deducting tax-allowable expenses — this is the base the 17% rate is applied to.
Dormant companies can apply for a waiver of Form C, but the waiver itself needs to be filed and approved — it isn’t automatic.
