Guide · Singapore · Accounting

Form C-S 2026: What Your Singapore Pte. Ltd. Must File by 30 November

Updated · 8 min read · Sources: IRAS, ACRA, MOF

Deadline

Your case

Deadline cockpit · YA 2026
Financial year ended on
Dormant company (no business activity, no income)?
Revenue in the financial year
Form
Form C-S
YA 2026

Only income taxable at 17%, no loss carry-back, no group relief, no investment allowance, no foreign tax credits. Otherwise Form C.

ECI deadline
31 Mar 2026
3 months after the financial year end. Waived only with revenue of S$5 million or less and an ECI of nil (before tax exemptions); the company checks this itself.
Filing deadline
30 Nov 2026
online via mytax.iras.gov.sg
via #SFFS software: 15 Dec 2026

Marked in the article:Choice of formExample tableECI rule#SFFS 15 Dec 2026

Guidance only, not tax advice.

Short answer

Every Singapore Pte. Ltd. must file its corporate income tax return for Year of Assessment (YA) 2026 online via mytax.iras.gov.sg by 30 November 2026. This also applies if the company made a loss or had no business activity, unless the tax authority IRAS has granted a waiver. The directors are responsible, even if a tax agent prepares the return.

01

Who must file Form C-S by 30 November?

Every company registered in Singapore whose financial year ended in 2025. Whether it made a profit, a loss or had no revenue at all does not matter.

  • Dormant companies file the simplified Form for Dormant Company instead of Form C-S (two mandatory fields, no financial statements). Only a company that has received a waiver from IRAS is exempt from filing.
  • Note: Even interest income, for example from a fixed deposit, ends dormant status. A company that is only looking for business is also treated as active.
  • Newly incorporated companies file for YA 2026 only if their first financial year ended in 2025 and they had income or commenced business in 2025.
02

Form C-S, C-S (Lite) or Form C: which form applies?

This depends on revenue and on the type of income.

Choice of form
FormWhenWhat you submit
Form C-S (Lite)Revenue of S$200,000 or less and all conditions for Form C-S met6 mandatory fields; keep financial statements and tax computation ready, do not upload
Form C-SYour caseRevenue of S$5 million or less, only income taxable at 17%, no loss carry-back, no group relief, no investment allowance, no foreign tax creditsForm; keep financial statements and tax computation ready
Form CAll other companiesForm with financial statements, tax computation and supporting schedules
Form for Dormant CompanyNo business activity and no income during the entire financial year2 mandatory fields, no financial statements

Source: IRAS, Corporate Income Tax Filing Season 2026 · As at 29 Sep 2026

What ongoing accounting and tax filing in Singapore involves is set out on our service page.

03

Which financial year counts? Singapore's YA logic

Singapore taxes the income of the financial year that ended in the previous year. Year of Assessment 2026 therefore covers the financial year that ended in 2025, regardless of the month.

Deadline ring 2025–202624 months · markers for your case (choose in the cockpit above)

  • Financial year end 31 Dec 2025
  • ECI deadline 31 Mar 2026
  • Form C-S 30 Nov 2026
  • via #SFFS software 15 Dec 2026
Timeline with the markers financial year end, ECI deadline (3 months later) and Form C-S 30 Nov 2026. The text version is in the table below.

Text version

Examples: financial year, Year of Assessment and deadlines
Financial yearYear of AssessmentECI due (without exemption)Form C-S due
1 Jan–31 Dec 2025Your caseYA 202631 Mar 202630 Nov 2026
1 Oct 2024–30 Sep 2025YA 202631 Dec 202530 Nov 2026
1 Jul 2024–30 Jun 2025YA 202630 Sep 202530 Nov 2026
1 Apr 2024–31 Mar 2025YA 202630 Jun 202530 Nov 2026

Source: derived from IRAS, Basic Guide to Corporate Income Tax and ECI Filing · As at 29 Sep 2026

A first financial year of more than 12 months is split across two Years of Assessment.

04

The second deadline: Estimated Chargeable Income (ECI)

Estimated Chargeable Income (ECI) is due within three months after the financial year end. It is waived only if both conditions are met: revenue of S$5 million or less and an ECI of nil, calculated before tax exemptions. The company checks this itself. Form C-S by 30 November remains mandatory regardless.Your case

05

Singapore corporate tax: rate and relief for YA 2026

Tax rate and relief YA 2026
RuleConditionSourceAs at
Corporate income tax 17%On chargeable income, for all companiesIRAS29 Sep 2026
Partial Tax Exemption: 75% of the first S$10,000 and 50% of the next S$190,000 exemptFor companies not using the Start-up Tax Exemption, including non-resident companiesIRAS29 Sep 2026
Start-up Tax Exemption: 75% of the first S$100,000 and 50% of the next S$100,000 exemptOnly in the first three YAs, only if tax resident in Singapore, no more than 20 shareholders, at least one individual holding 10%; not for investment holding companies and property developersIRAS29 Sep 2026
CIT Rebate of 50% of tax payable, capped at S$40,000 together with the CIT Rebate Cash GrantCalculated automatically in the assessment; no tax payable, no rebateIRAS, MOF (increased on 7 Apr 2026)29 Sep 2026
CIT Rebate Cash Grant of S$2,000Only for active companies that made CPF contributions in 2025 for at least one local employee; shareholder-directors do not countIRAS29 Sep 2026

Not yetNot yet for this return: the AI deduction announced in Budget 2026 (400% on up to S$50,000 of AI expenditure per year) applies only for YA 2027 and YA 2028.

06

Managed from Germany, the EU or elsewhere: why the place of decision-making matters

According to IRAS, a Singapore company is tax resident only if its control and management is exercised there, meaning its strategic decisions. This is usually where board meetings are held; incorporation in Singapore alone is not enough. Virtual meetings count as held in Singapore if at least half of the directors or the chairman are physically there.

Without tax residency, the Start-up Tax Exemption and the Certificate of Residence are among the things that are not available. The obligation to file Form C-S remains. What applies in your home country depends on where the company is actually managed. Many countries link a company’s tax liability to the place of its management:

Tax liability linked to the place of management
CountryWhat tax liability is linked toLegal basis
GermanyManagement (centre of top-level business management) or registered office in Germany: unlimited corporate income tax liability§ 10 AO, § 1 KStG
AustriaManagement or registered office in Austria; the place of management is the centre of top-level business management§ 27 Abs. 2 BAO, § 1 Abs. 2 KStG 1988
SwitzerlandRegistered office or effective administration in SwitzerlandArt. 50, 52 DBG
United KingdomCentral management and control in the UK (HMRC practice based on case law)HMRC INTM120060
EU member statesCFC rules mandatory since 2019: with a holding of more than 50%, profits of a controlled foreign company can be taxed at shareholder level if the tax actually paid abroad is lower than the difference between the domestic tax and the tax actually paid; the directive applies to shareholders subject to corporate income taxDirective (EU) 2016/1164 (ATAD), Art. 7, 8, 11

Source: official legislation and administrative guidance (gesetze-im-internet.de, RIS, Fedlex, HMRC, EUR-Lex) · As at 29 Sep 2026

If two countries both treat the same company as resident, the double tax treaty decides. Under the treaty texts with Singapore, Germany, Austria and Switzerland each use the place of effective management (Art. 4(3) of each treaty). This is an overview, not an assessment of your individual case. We clarify that in the consultation.

How to set up a Singapore company properly from the start is covered under company formation in Singapore. Whether Singapore or Hong Kong fits your plans better is shown in the jurisdiction comparison.

07

What happens if you file Form C-S late?

Late filing is an offence. IRAS may issue an estimated Notice of Assessment, which must be paid within one month, even if you object. A composition of up to S$5,000 per offence and a summons to court are also possible. A company that fails to file for two years or more risks a penalty of twice the amount of tax assessed.

An extension for the current year can only be requested after 30 November, and IRAS decides case by case whether to grant it. A company that files Form C-S through approved accounting software (#SFFS) automatically has until 15 December.Your case

To do by 30 November

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Frequently asked questions about Form C-S

Do I have to file Form C-S if my company had no revenue?

Yes, unless IRAS has granted a waiver. Dormant companies use the simplified Form for Dormant Company. Even interest income ends dormant status.

When is Form C-S for YA 2026 due?Your case

By 30 November 2026, online via mytax.iras.gov.sg. A company that files through approved accounting software (#SFFS) automatically has until 15 December 2026.

What is the difference between ECI and Form C-S?

ECI is an estimate, due three months after the financial year end. Form C-S is the actual tax return, due on 30 November. An ECI waiver does not exempt the company from Form C-S.

Will my company receive the S$2,000 CIT Rebate Cash Grant?

Only if it is active and made CPF contributions in 2025 for at least one local employee. Shareholder-directors do not count. The CIT Rebate of 50% of tax payable applies independently of this.

Does the Start-up Tax Exemption apply if I manage the company from abroad?

Only if the company is tax resident in Singapore in the relevant year, meaning its strategic decisions are made in Singapore. The filing obligation applies regardless.

Can I already use the 400% AI deduction?

Not for YA 2026. The deduction applies only for YA 2027 and YA 2028, i.e. to financial years ending in 2026 and 2027.

Review note

Editorial
Strasia Group
Sources
IRAS, ACRA, MOF
Updated
Next review
after Singapore Budget 2027

Deadline in view, paperwork still open?

In a free first consultation (60 minutes) we clarify which form applies to your company and what is still missing before 30 November.

Read on: Singapore accounting · Singapore company formation · How much tax you will pay: rates and calculator · The Hong Kong counterpart: audit, PTR and NAR1 · All guides

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