Form C-S

Single Filing Deadline from 2021

From the Year of Assessment (YA) 2020, e-Filing of Form C-S/ C is compulsory for all companies

The extended filing deadline of 15 Dec, which was initially introduced in 2012 to encourage companies to e-File their Corporate Income Tax returns, will no longer be available from 2021. From YA 2021, all companies will be required to e-File their Corporate Income Tax returns by 30 Nov 2021.

The e-Service File Form C-S for YA 2020 is available at now.

Form C-S is a simplified income tax return for companies to report their income to IRAS. Qualifying companies may use Form C-S, instead of Form C, to report their income.

Find out more about the e-Service and Tips on e-Filing Form C-S.

To further enhance the e-Filing experience of small companies, companies that qualify to file Form C-S and have an annual revenue of $200,000 or below now have the option to file Form C-S (Lite). 

Form C-S (Lite) is a simplified version of Form C-S that requires only six essential fields to be completed and is suitable for companies with straight-forward tax matters.

Find out more about Form C-S (Lite).

Removal of Downloadable Form C-S

In line with compulsory e-Filing, the downloadable Form C-S will not be available on the IRAS website. Qualifying companies may e-File Form C-S via myTax Portal.   

Pre-Filled Information

To improve companies' e-Filing experience, the following amounts will be pre-filled in the Form C-S or Form C-S (Lite), where available:

  • Unutilised Capital Allowances brought forward
  • Unutilised Losses brought forward
  • Unutilised Donations brought forward
  • Current year Approved Donations

The pre-filling is based on the carried forward amounts in the last assessment raised by IRAS for the immediate preceding YA. This will apply even if the assessment for the immediate preceding YA is under objection or query.

If the return for the immediate preceding YA is under review, the pre-filling will be based on the carried forward amounts declared in the Form C-S (Lite)/ C-S/ C of the immediate preceding YA.

The amounts are pre-filled for the companies' easy reference. You are advised to verify the accuracy of the information. In case of any discrepancy in the details (i.e. the companies' carried forward amounts in their own records differ from the pre-filled records), you may update the pre-filled sections in the relevant Boxes under "Company's Declaration" (with the exception of donations).

The 250% deduction for donations is granted based on information obtained from the Institutions of a Public Character (IPCs). You can view details of the current year approved donation amounts in the View Donations e-Service.

If the company has made an approved donation, but it is not reflected in the View Donations e-Service at, it may be due to:

  1. Differences in receipting date - The IPC may have recorded your donation in a later financial period and a deduction would be accorded in the corresponding YA.
  2. You did not provide your company's Unique Entity Number (UEN) to the IPC. Please update your donation record with the IPC and IRAS will amend your assessment when we received the updated record.

If the company adopted a non-Singapore Dollar functional currency for the financial period and the approved donations are reflected in the View Donations e-Service at, please ensure that the “Functional Currency” in the Corporate Profile Page is updated accordingly. You will then be allowed to input the Singapore dollar equivalent amount of your current year donation in the “Company’s Declaration” box.

Please e-File the Form C-S or Form C-S (Lite) via myTax Portal by the filing due date to avoid enforcement actions such as composition or summons issued to the company.

Recommencing Business

If your company was dormant and had previously been granted a waiver to file Income Tax Return, but has now recommenced business or is in receipt of income, please notify IRAS within one month from the date of commencement of business or earning/ receiving the income by sending an email to to request for an Income Tax Return. Please provide all the following details (indicate "N/A" if not applicable):

a. Subject header: “Recommencement of business and request for Income Tax Return”
b. Name and Unique Entity Number (UEN) of the company;
c. Date of recommencement of business in dd/mm/yyyy format;
d. Date of receipt of other source(s) of income (e.g. interest, dividend, rent, etc.) in dd/mm/yyyy format; and
e. New principal activity and the effective date of change in dd/mm/yyyy format together with a copy of BizFile extracted from ACRA showing the principal activity of the company.

Basic Corporate Tax Calculator

The Basic Corporate Tax Calculator is designed for trading companies and it comes with commonly used schedules such as the capital allowance schedule. You can use it to prepare your company’s tax computation and work out the tax payable before completing Form C-S. 

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