Every Singapore company files a corporate income tax return with IRAS by 30 November. For Year of Assessment (YA) 2026, that return covers your financial year ending in 2025. The form depends mainly on your revenue and on what your company claims.
The three forms
| Form | Who can use it | What you submit |
|---|---|---|
| Form C-S (Lite) | Revenue of S$200,000 or less, and meets the Form C-S conditions | Six key figures; accounts and tax computation kept, not filed |
| Form C-S | Revenue of S$5 million or less, Singapore-incorporated, income taxed only at 17%, none of the excluded claims | 18 key figures; accounts and tax computation kept, not filed |
| Form C | Every other company | The return with financial statements and tax computation |
Excluded claims for Form C-S include group relief, investment allowance, foreign tax credit and carry-back of current-year capital allowances or losses. A company claiming any of these files Form C.
How the tax is worked out
- Headline rate: 17%.
- Partial tax exemption: 75% of the first S$10,000 and 50% of the next S$190,000 of chargeable income are exempt.
- Start-up tax exemption: for a qualifying new company's first three YAs, 75% of the first S$100,000 and 50% of the next S$100,000 are exempt.
- YA 2026 rebate: 40% of tax payable, capped at S$30,000, announced in Budget 2026.
Before you file
- Reconcile bank accounts and close the year in your books.
- Separate non-deductible expenses such as private car costs and fines.
- List capital purchases for capital allowances.
- Confirm that GST returns agree with revenue.
Run the numbers with our free Singapore corporate tax calculator, or ask us to prepare the return.
Frequently asked questions
By 30 November each year, filed on myTax Portal.
No. Form C-S and C-S (Lite) companies keep their financial statements and tax computation and provide them if IRAS asks.
