How Singapore corporate income tax works
Corporate tax starts with the company's accounting results, but accounting profit is not automatically the amount that is taxed. A tax computation adjusts the accounts for items treated differently for tax purposes, then applies available deductions, capital allowances, exemptions and reliefs.
Singapore uses a single-tier corporate tax system. Tax paid by a Singapore company on its profits is final at the company level, and dividends paid by a Singapore resident company under the one-tier system are generally not taxed again in the hands of shareholders.
Financial year, basis period and Year of Assessment
The financial year is the period covered by the company's accounts. The basis period is the period of income used for a particular Year of Assessment. The Year of Assessment is the year in which that income is assessed to tax.
Example: A company with a financial year from 1 January 2025 to 31 December 2025 will normally have that income assessed in YA 2026.
If you are choosing or changing your financial year end, see our guide to choosing a financial year end.
What is the corporate income tax rate in Singapore?
The prevailing corporate income tax rate is 17%. That is the headline rate, not necessarily the effective rate a company ultimately pays.
Start-Up Tax Exemption
For qualifying new companies in their first 3 consecutive YAs, 75% of the first S$100,000 of normal chargeable income is exempt, followed by a 50% exemption on the next S$100,000. Conditions apply. The company must, among other things, be incorporated in Singapore, be tax resident in Singapore for the relevant YA and meet the shareholder conditions. Investment holding companies and companies undertaking property development for sale, investment or both are excluded.
Partial Tax Exemption
For companies that do not claim the start-up exemption, 75% of the first S$10,000 of normal chargeable income is exempt, followed by a 50% exemption on the next S$190,000.
What income is actually taxable?
A company's tax computation starts with its accounting profit or loss and makes the necessary tax adjustments. Not every accounting expense is tax-deductible, and some deductions are claimed through tax rules rather than simply following the accounting treatment.
Common adjustments can involve non-deductible expenses, capital expenditure and capital allowances, private or non-business expenditure, provisions, foreign income, donations, research and development claims and unutilised losses or allowances.
Singapore does not impose a separate capital gains tax. That does not mean every gain from selling an asset is automatically outside income tax. Whether a gain is capital or revenue in nature depends on the circumstances and applicable tax rules.
Corporate tax filing happens in two stages
Estimated Chargeable Income (ECI) is an estimate of the company's taxable profits for the YA. It is due within 3 months after the financial year end unless an ECI filing waiver applies or the company is specifically not required to file. The waiver applies where annual revenue is S$5 million or below for the financial year and ECI is nil for the YA. Our ECI guide covers this in detail.
The final Form C-S (Lite), Form C-S or Form C declares the company's actual taxable income for the YA and is due by 30 November each year.
Which corporate income tax return do you file?
- Form C-S (Lite) is available to qualifying companies with annual revenue of S$200,000 or below.
- Form C-S is available to qualifying companies with annual revenue of S$5 million or below.
- Form C is used where the company does not meet the Form C-S eligibility conditions.
The shorter forms simplify filing for eligible companies, but they do not remove the need to prepare proper accounts and tax computations.
When is the tax actually paid?
Filing a return and paying the assessed tax are separate steps. IRAS issues a Notice of Assessment after assessing the return. The tax stated in the notice is generally payable within 1 month from the date of the Notice of Assessment, even if the company objects to the assessment.
See our guide on paying Singapore corporate income tax for the payment process.
Tax residency is different from incorporation
A company can be incorporated in Singapore without automatically being Singapore tax resident. IRAS generally determines corporate tax residency by where the company's control and management is exercised. Residency can affect access to Singapore's tax treaties and certain tax exemptions or foreign-income reliefs.
A simple annual corporate tax timeline
- Close the financial year and complete the accounting records.
- File ECI within 3 months after FYE, unless a waiver or specific non-filing rule applies.
- Prepare the final tax computation based on the completed accounts and applicable tax adjustments.
- File Form C-S (Lite), Form C-S or Form C by 30 November.
- Review the Notice of Assessment issued by IRAS.
- Pay the assessed tax by the payment deadline.
Need help with the tax computation and filing?
If your accounts are ready and you would like us to handle the tax computation, ECI and annual IRAS filing, see our corporate tax filing and computation service. If you are unsure what is outstanding for a particular YA, contact us and we would be happy to go through it with you.
Official references: IRAS Basic Guide to Corporate Income Tax; IRAS Corporate Income Tax Rates; IRAS ECI Filing.
