- Simpler Tax
- Form C-S, C-S (Lite) or Form C
Form C-S, Form C-S (Lite) or Form C: which one do I file, and what goes in each box?
File Form C-S if your company is incorporated in Singapore, its revenue for the financial year is S$5,000,000 or below, all of its income is taxed at the 17% rate, and it is not claiming carry-back of this year's capital allowances or losses, group relief, investment allowance, foreign tax credit or tax deducted at source. If revenue is also S$200,000 or below you may file the shorter Form C-S (Lite) instead, and a company that fails any one of those tests files Form C.
All three are due on 30 November of the year of assessment, and for YA 2026 that is 30 Nov 2026.
Computed from the rulebook Edition YA-2027 · sources verified through 24 Jul 2026
Which form
The three returns ask for the same computation at three levels of detail. The tests are IRAS's; a company that passes them all may still choose the longer form, but not the shorter.
| Return | Who files it | What it asks for |
|---|---|---|
| Form C-S (Lite) | Every Form C-S condition, and revenue of S$200,000 or below | 6 fields. Optional: a company that qualifies may still file the full Form C-S |
| Form C-S | Incorporated in Singapore; revenue of S$5,000,000 or below; every dollar of income taxed at the 17% rate; not claiming carry-back of this year's capital allowances or losses, group relief, investment allowance, foreign tax credit or tax deducted at source | Part A declarations, Part B items 1 to 20, Part C figures from the accounts. The tax computation is kept, not attached |
| Form C | Any company that fails one of those tests, and every foreign-incorporated company or branch, at any revenue | The full return, with the tax computation and the financial statements attached |
Revenue here means the income from the company's principal activity, so interest or rent on the side does not count towards the cap; for an investment holding company, its investment income is its revenue. Foreign-incorporated companies and Singapore branches are never eligible for Form C-S, whatever their size.
What goes in each box of Form C-S
Form C-S has three parts. Part A is declarations: the eligibility tests above, who reviewed the return, and the financial period it covers. Part B is the tax computation, items 1 to 20, which turns the profit in your accounts into the profit IRAS taxes. Part C is figures copied from the financial statements: revenue, gross profit, directors' remuneration, total remuneration, medical, transport and entertainment expenses, inventories and trade receivables, and a few yes-or-no declarations.
Part B is the part people get wrong, so here it is line by line, with the worked company's figures beside each item. Items that stay zero for a plain trading company are shown as 0.00.
| Item | What goes in it | Worked, S$ |
|---|---|---|
| 1 | Net profit/loss before tax per financial statements | 120,000.00 |
| 2 | Less: separate source income | 0.00 |
| 3 | Less: non-taxable income | 0.00 |
| 4 | Add: non-tax-deductible expenses | 15,000.00 |
| 5 | Adjusted profit/loss before other deductions | 135,000.00 |
| 6 | Less: S14N renovation & refurbishment | 0.00 |
| 7 | Less: EIS enhanced deductions | 0.00 |
| 8 | Less: further deductions | 0.00 |
| 9 | Adjusted profit/loss before capital allowances | 135,000.00 |
| 10 | Add: balancing charge | 0.00 |
| 11 | Less: unutilised capital allowances b/f | 0.00 |
| 12 | Less: current year capital allowances | 0.00 |
| 13 | Less: unutilised losses b/f | 0.00 |
| 14c | Add: net rental income | 0.00 |
| 15 | Add: interest income | 0.00 |
| 16 | Add: other taxable income | 0.00 |
| 17 | Total income before donations | 135,000.00 |
| 18 | Less: unutilised donations b/f | 0.00 |
| 19a | Less: IPC donationsApproved IPC donations count 2.5 times; you enter the amount given and the 250% is applied in the computation. | 0.00 |
| 19b | Less: PTIS/OHAS donations | 0.00 |
| 20 | Chargeable income before exempt amountThis is the chargeable income before the exempt amount, the figure the ECI estimates and the figure the exemption is taken from. | 135,000.00 |
Three items carry forward rather than into the tax: unutilised capital allowances, losses and donations that this year could not absorb. For the worked company they are all zero, because it had a profit.
| Item | What goes in it | Worked, S$ |
|---|---|---|
| 21 | Unutilised capital allowances c/f | 0.00 |
| 22 | Unutilised losses c/f | 0.00 |
| 23 | Unutilised donations c/f | 0.00 |
A worked example for YA 2026
A Singapore Pte Ltd with S$800,000.00 of sales and S$120,000.00 of profit
Its accounts for the financial year ending in 2025 show revenue of S$800,000.00 and a net profit before tax of S$120,000.00. The only tax adjustment is S$15,000.00 of depreciation, which is not deductible and is added back (its assets were fully written off for tax in earlier years, so there is no capital allowance to claim this year). It has one local employee on CPF and is past its first three years, so it gets the partial tax exemption, not the start-up one.
Revenue is under S$5,000,000 and over S$200,000, so it files Form C-S. Item 5, the adjusted profit, is S$135,000.00: the S$120,000.00 in the accounts plus the S$15,000.00 added back. Nothing else moves it, so item 20, the chargeable income before exemption, is also S$135,000.00.
| Step | Arithmetic | S$ |
|---|---|---|
| Chargeable income before exemption (item 20) | 135,000.00 | |
| Exempt: 75% of the first S$10,000 | 75% of 10,000.00 | 7,500.00 |
| Exempt: 50% of the next S$190,000 | 50% of 125,000.00 | 62,500.00 |
| Less: exempt amount (partial tax exemption) | 7,500.00 + 62,500.00 | 70,000.00 |
| Chargeable income after exemption | 135,000.00 − 70,000.00 | 65,000.00 |
| Tax at 17% | 65,000.00 × 17% | 11,050.00 |
| Corporate income tax rebate, 50% of the tax | 11,050.00 × 50%, capped at S$40,000 together with the cash grant | 5,525.00 |
| Of which the cash grant, paid to the company by IRAS | Needs at least one local employee on CPF in 2025, not counting shareholder-directors | 2,000.00 |
| Less: rebate taken off the bill | 5,525.00 − 2,000.00 | 3,525.00 |
| Tax payable | 11,050.00 − 3,525.00 | 7,525.00 |
The bill is S$7,525.00, and IRAS separately pays the company the S$2,000.00 cash grant, so the YA 2026 rebate is worth S$5,525.00 in total. A company with no local employee gets no cash grant and takes the whole S$5,525.00 off the bill instead: tax payable S$5,525.00, the same S$5,525.00 of relief by one route rather than two.
The exemption every company gets, and the bigger one for new ones
The partial tax exemption is automatic: 75% of the first S$10,000 and 50% of the next S$190,000 of chargeable income is exempt, so up to S$102,500 a year is never taxed. It is taken off item 20 before the 17% is applied, as the worked table shows.
A new company can do better for its first 3 years of assessment: the start-up tax exemption is 75% of the first S$100,000 and 50% of the first S$100,000, up to S$125,000 a year. It needs the company to be incorporated in Singapore and tax resident here, to have no more than 20 shareholders who are all individuals (or at least one individual holding 10% or more), and not to be an investment holding or property development company.
When and where
Form C-S, Form C-S (Lite) and Form C are all due on 30 November of the year of assessment: for YA 2026, 30 Nov 2026. You file at myTax Portal with your Corppass; paper filing ended with YA 2020.
For Form C-S the tax computation is not attached. You keep it, with the supporting schedules, and produce it if IRAS asks. For Form C the computation and the financial statements go in with the return, as PDFs.
Late filing draws a composition fine or a summons, and IRAS may assess you on an estimate that is payable regardless. An incorrect return can cost up to twice the tax undercharged.
The Form C-S pack, every item computed from your own books
Post the year's documents and the Tax screen issues the Form C-S pack: items 1 to 23 and the tax below them, each derived from posted entries and each with a copy button. You type them into myTax Portal and sign. Simpler Tax files nothing and holds no Corppass credentials; it prepares the figures and shows the working behind every one of them.
Download for WindowsQuestions people ask
Is Form C-S (Lite) compulsory if my revenue is under S$200,000?
No. Form C-S (Lite) is optional for a company with revenue of S$200,000 or below that meets every Form C-S condition. You may file the ordinary Form C-S instead, and the figures are the same either way; Lite asks for 6 of them.
My revenue went over S$5 million this year. Do I switch to Form C?
Not yet. A company that filed Form C-S may stay on it for one further year of assessment after its revenue passes S$5,000,000, provided the other conditions still hold. If revenue is over the cap again the year after, it files Form C.
Do I have to file if the company made a loss or did no business?
Yes. Every company files a corporate income tax return each year of assessment, including one that traded at a loss or did nothing. A company that did no business can ask IRAS for a waiver of the return; until that is granted, the return is due.
What is the corporate tax rate in Singapore?
17% of chargeable income after the exempt amount. Every company gets the partial tax exemption, 75% of the first S$10,000 and 50% of the next S$190,000, so the tax on the worked company's S$135,000.00 of chargeable income comes to S$7,525.00 after the YA 2026 rebate, about 7.1% of it.
Which year of assessment am I filing by 30 Nov 2026?
YA 2026, which covers the financial year that ended in 2025. The year of assessment is always the calendar year after the one your financial year ended in.
When is Form C-S due?
30 November of the YA each year, and for YA 2026 that is 30 Nov 2026. Form C-S (Lite) and Form C are due the same day. Filing is online only, at myTax Portal, since YA 2020.
Sources
Statutory figures on this page are read from the Simpler Tax rulebook at build time, edition YA-2027, every source last checked 24 Jul 2026. The rulebook entries named below are the ones this page was computed from; the IRAS pages are what they were verified against.
- IRAS, Overview of Form C-S / Form C-S (Lite) / Form C
https://www.iras.gov.sg/taxes/corporate-income-tax/form-c-s-form-c-s-(lite)-form-c-filing/overview-of-form-c-s-form-c-s-(lite)-form-c - IRAS, Explanatory notes to the YA 2026 Form C-S (the Part B item list)
https://www.iras.gov.sg/docs/default-source/uploadedfiles/pdf/explanatory-notes-to-ya-2026-form-c-s.pdf - IRAS, Guidance on filing Form C-S / Form C-S (Lite) / Form C
https://www.iras.gov.sg/taxes/corporate-income-tax/form-c-s-form-c-s-(lite)-form-c-filing/guidance-on-filing-form-c-s-form-c-s-(lite)-form-c - Form C-S eligibility and the revenue cap rulebook forms.cs.eligibility
- Form C-S (Lite) revenue cap and field count rulebook forms.cs-lite
- Filing deadline and e-filing rulebook forms.filing-deadline
- Corporate income tax rate rulebook cit.rate.headline
- Partial tax exemption tiers rulebook cit.pte
- Start-up tax exemption tiers and conditions rulebook cit.sute
- YA 2026 corporate income tax rebate and cash grant rulebook cit.rebate.ya2026.enhanced