CORPORATE TAX COMPARISON · YA 2026
Form C-S vs Form C-S (Lite) vs Form C
The right return depends on more than revenue. Use this guide to identify which form fits your Singapore company—and what must be prepared before filing.
QUICK ANSWER
Start with Form C-S eligibility. Then check revenue.
S$200,000 or below
If all C-S conditions are met, choose Form C-S (Lite) or Form C-S.
Above S$200,000 to S$5m
If all other conditions are met, file Form C-S.
Does not meet C-S rules
File Form C, regardless of whether revenue is below S$5 million.
SIDE-BY-SIDE
What changes between the three returns.
| Feature | Form C-S (Lite) | Form C-S | Form C |
|---|---|---|---|
| Revenue | S$200,000 or below | S$5 million or below | No revenue cap |
| C-S conditions | Must meet all | Must meet all | Not required |
| Return length | 6 essential fields | Simplified return | Full return |
| Financial statements | Prepare and retain | Prepare and retain | Prepare and submit |
| Tax computation | Prepare and retain | Prepare and retain | Prepare and submit |
| Annual deadline | 30 November | 30 November | 30 November |
Source: IRAS overview of Form C-S, Form C-S (Lite) and Form C.
FORM C-S CHECKLIST
All four conditions must be satisfied.
- 01The company is incorporated in Singapore.
- 02Annual revenue is S$5 million or below.
- 03Income is taxable only at the prevailing 17% corporate tax rate, subject to IRAS’s stated exceptions.
- 04The company is not claiming current-year loss or capital-allowance carry-back, group relief, investment allowance, foreign tax credit or tax deducted at source.
The common trap
A Singapore-incorporated company with S$1 million revenue may still need Form C if, for example, it is claiming group relief or foreign tax credit. Passing the revenue test does not override the other conditions.
DOCUMENTS
“No attachment” does not mean “no preparation.”
C-S and C-S (Lite)
Prepare financial statements, a tax computation and supporting schedules. Keep them ready for submission if IRAS requests them.
Form C
File the financial statements, detailed profit and loss statement, tax computation, supporting schedules and applicable claim forms with the return.
Common questions.
Is Form C-S (Lite) a different tax scheme from Form C-S?
No. Form C-S (Lite) is a shorter version of Form C-S. A company must first qualify for Form C-S and have annual revenue of S$200,000 or below before it can choose the Lite return.
Does revenue below S$5 million guarantee Form C-S eligibility?
No. Revenue is only one condition. The company must also be incorporated in Singapore, derive only qualifying income taxable at the prevailing corporate tax rate, and not make certain claims listed by IRAS.
Do I attach financial statements when filing Form C-S?
Generally, no. Form C-S and Form C-S (Lite) filers prepare and retain their financial statements, tax computation and supporting schedules, then submit them if IRAS asks. Form C filers submit the required documents with the return.
Can a loss-making company use Form C-S?
Potentially, yes, if it meets all Form C-S conditions. However, a company claiming carry-back of current-year losses or capital allowances does not qualify for Form C-S.
When is the corporate income tax return due?
Form C-S, Form C-S (Lite) and Form C are due by 30 November each year. This is separate from any ECI filing due within three months after the financial year end.
Do not forget the earlier ECI deadline.
Your annual return choice does not replace ECI. Check its due date and the common waiver separately.
Calculate both company deadlines