The deadline for filing your Corporate Income Tax Return (Form C-S/ Form C-S (Lite)/ Form C) for the Year of Assessment (YA) 2021 is 30 Nov 2021.

Electronic filing of Form C-S/ Form C-S (Lite)/ Form C is compulsory for all companies.

Key Tax Changes for YA 2021

  • Companies are given the option to claim the Renovation & Refurbishment (R&R) deduction in 1 YA (i.e. accelerated R&R deduction) instead of over 3 YAs for qualifying R&R expenditure incurred during the basis period for YA 2021.
  • Companies are given an option to accelerate the write-off of plant and machinery (P&M) over 2 years, instead of 3 years or the prescribed working life of the asset, on the cost incurred in acquiring such P&M during the basis period for YA 2021.
  • Companies may elect for either the current Carry-Back Relief or enhanced Carry-Back Relief for YA 2021.

Filing of the Corporate Income Tax Return

How do I file via

In order to file via, you have to first be authorised by your company to act for its Corporate Income Tax matters via Corppass. View our step-by-step guides for assistance on Corppass setup.  

Which Corporate Income Tax Return should I file (Form C-S, Form C-S (Lite) or Form C)?

Form C-S is for companies that:

  • Are incorporated in Singapore;
  • Have an annual revenue of $5 million or below;
  • Derive income taxable at the prevailing Corporate Income Tax rate of 17%; and
  • Are not claiming the following:
    • Carry-back of Current Year Capital Allowances/ Losses
    • Group Relief
    • Investment Allowance
    • Foreign Tax Credit and Tax Deducted at Source

Form C-S (Lite) is for companies that qualify to file Form C-S and have an annual revenue of $200,000 or below.

Form C is for companies that do not qualify to file Form C-S or Form C-S (Lite). Financial statements, tax computations and supporting schedules must be filed together with Form C.

Do I need to file my Corporate Income Tax Return for YA 2021?

Company was newly incorporated in 2020

Yes,  if your company closed its first set of financial statements  in  2020,  and  derived  income  or  started business in 2020.

Visit our Basic Guide to Corporate Income Tax for Companies page where you can get help with filing your company’s tax returns for the first time. You can also access the New Company Start-Up Kit, an interactive guide to learn more about Corporate Income Tax filing obligations. It customises your filing information, provides useful tips and generates email reminders about your tax filing obligations.


Year of IncorporationYear the first set of Accounts is ClosedDo I need to file for YA 2021?What needs to be done
  • File your YA 2021 Corporate Income Tax Return
  • Apportion your profits/ losses to YAs 2020 and 2021 if your first set of accounts covers more than 12 months
20202020Yes, if your company commenced business or received income in 2020
  • File your YA 2021 Corporate Income Tax Return
  • No action required
  • No action required

Company was in a loss position for the financial year 2020

Yes, you have to file your Corporate Income Tax Return as long as you have carried out business.

Company was dormant for the financial year 2020

Yes, you have to file your Corporate Income Tax Return, unless your company has been granted a waiver to file the return.

If  your  company  did  not  carry  on  business  and  had  no  income  for  the  whole  financial  year  2020,  it  is regarded as a dormant company for YA 2021. You may file your Corporate Income Tax Return using the File Form for Dormant Company digital service at

Learn more about dormant companies.

Company's YA 2020 tax assessment is currently under IRAS' review

Yes, you have to file the YA 2021 Corporate Income Tax Return based on the YA 2020 tax position filed with IRAS. The same deadline of 30 Nov 2021 applies. 

Any unutilised loss items and tax written down values of assets (for the purposes of computing capital allowances) to be carried forward to YA 2021, for set-off against the taxable income of YA 2021, should be based on the YA 2020 tax computation prepared by your company.  

When filing, the brought forward unutilised amounts in the current YA fields will be pre-filled with the carried forward amounts declared by the company in the YA 2020 Form C-S/ Form C-S (Lite)/ Form C.

Learn more about the Corporate Income Tax Return review process.

Preparing a Tax Computation

What income is taxable?

Taxable income refers to:

  • Gains or profits from any trade or business
  • Income from investment such as dividends, interest and rental
  • Royalties, premiums and any other profits from property
  • Other gains that are revenue in nature

Such income is taxed when it is:

  • Accrued in or derived from Singapore; or
  • Received in Singapore from outside Singapore

Learn more about taxable and non-taxable income or watch this video on the Taxability of Income (5m 44s).

What expenses are deductible and what are the common tax reliefs and deductions for companies?

You may claim tax deductions on expenses 'wholly and exclusively' incurred in the production of income.

Learn more about the deductibility of expenses and the tax reliefs available to lower your tax burden. You may also watch this video on the Tax Deductibility of Expenses (4m 59s).

What are the common filing mistakes to avoid?

  • Wrongful claims of non-deductible expenses:
    • Interest expenses attributable to non-income producing assets or investments that produce exempt dividends
    • S-plated cars purchased for business use, including the cost of the car and the associated running expenses
  • Understatement of income (e.g. omission of particular receipts or invoices issued or transactions settled in cash)
  • Failure to keep proper records and accounts, resulting in the understatement of sales or overstatement of expenses in tax returns

View common Corporate Income Tax Return filing mistakes.

How do I work out my company’s tax payable?

Use the IRAS Basic Corporate Income Tax Calculator to compute the amount of taxes your company has to pay. Explanatory notes to guide you through tax computation and validation checks against common errors are included in the calculator.

How do I prepare the tax computation for my investment holding company?

An investment holding company is a company that owns investments such as properties and shares for long term investment, and derives investment income (non-trade income) such as dividend, interest or rental income. 

Learn how to prepare the tax computation for your investment holding company.

Filing Status

How do I check the status of my Corporate Income Tax Return submission and assessment?

The status of your company's Corporate Income Tax Return and tax assessment can be found at or through the Corporate Income Tax Integrated Phone Service. Learn how to check your Form C-S/ Form C-S (Lite)/ Form C submission and assessment status.

Your company’s filing status may only be viewed at the View Corporate Tax Filing Status digital service at 3 working days after you have filed your company’s Form C-S/ Form C-S (Lite)/ Form C.

How do I make changes to my Corporate Income Tax Return submission?

Revise the amount declared and/or submit a revised tax computation via the Revise/ Object to Assessment digital service at Learn more about making changes to your company’s tax submission.

Tax Bill

When will I get my tax bill?

View the IRAS tax assessment process for an overview of the tax return review cycle and timeline that you can expect to get your tax bill, also known as the Notice of Assessment. After your Notice of Assessment is issued, you can access it via the View Notices/ Letters - Corporate Tax digital service at

What should I do if I do not agree with my tax bill?

File your objection via the Revise/ Object to Assessment digital service at within 2 months from the date of the Notice of Assessment if you wish to have your tax assessment reviewed and revised. 

Learn more about the objection and appeal process.

How do I pay my tax?

Payment must be made within 1 month from the date of the Notice of Assessment, notwithstanding any objections. Payment modes include GIRO (preferred), PayNow QR, AXS, Internet Banking and other electronic payment modes. 

Learn more about the payment methods for Corporate Income Tax.

How do I claim a refund for my tax credit?

Tax credits are automatically refunded within 30 days from the date the credit arose. There is no need to submit a claim.

If your company pays taxes through GIRO from its own bank account, it will receive the refund to the same bank account. For all other payment methods, you will receive a cheque that is valid only for 3 months from the date of issuance. 

Learn more about tax refunds.

Tax Assistance

Refer to the relevant guides for assistance to file your Corporate Income Tax Return:

Form C-S/ Form C-S (Lite)

Form C

User Guide - Form C-S/ Form C-S (Lite) (Company) (PDF, 1380KB)

How to File Form C-S/ Form C-S (Lite)

FAQs - File Form C-S (PDF, 390KB)

User Guide - Form C (Company) (PDF, 1996KB)

How to File Form C

FAQs - Form C (PDF, 411KB)

We encourage you to file early. Penalties and enforcement actions may be taken for late or non-filing of your company’s Corporate Income Tax Return.

For Form C-S filers, you can also use the digital solution created by IRAS and the Accounting and Corporate Regulatory Authority (ACRA). This solution allows companies to automate the preparation and filing of Form C-S and Annual Return with IRAS and ACRA respectively via accounting software. The digital solution leverages the Application Programming Interface (API) to simplify the tax filing process for companies and reduces their risk of making errors. Learn more about the digital solution.

You can also access our e-Learning videos to learn more about Corporate Income Tax.