Form C-S

Compulsory e-Filing for Form C-S/ C

As announced in Budget 2016, in line with Government's direction for more cost effective delivery of public services and the Smart Nation vision to harness technology to enhance productivity, e-Filing of Corporate Income Tax returns (including ECI, Form C and Form C-S) is made compulsory in phases from the Years of Assessment (YAs) 2018 to 2020 as follows:

YA Target Group 
2018 onwards Companies with revenue more than $10 million in YA 2017 
2019 onwards Companies with revenue more than $1 million in YA 2018 
2020 onwards All Companies 

The e-Service File Form C-S and softcopy of Form C-S in PDF format for the Year of Assessment (YA) 2019 are now available.

Form C-S is a simplified 3-page 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.

e-File Form C-S via and enjoy these benefits!

  • Auto-computation of certain fields that minimise filing errors
  • An instantaneous estimate of tax payable
  • iHelp for step-by-step guidance
  • Extra 15 days to file                                            

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

If your company cannot e-File Form C-S and does not fall within the compulsory e-Filing group for the relevant YA, you may download the softcopy of Form C-S by clicking on the relevant YA below:

Please complete, print and submit the signed Form C-S by the filing due date to avoid enforcement actions such as composition or summons issued to the company. 

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 the following details:

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 and new principal activity (if applicable); and
d. Date of receipt of other source(s) of income e.g. interest, dividend, rent, etc. (if applicable).

Document Identification Number (DIN)

DIN is a unique number code that is generated by IRAS to identify each Income Tax Return (Form C-S/ C) issued.

DIN is to be entered in the DIN worksheet of the Form C-S which you have downloaded. When you enter the DIN, it will be automatically populated on page 1 of the Form C-S.

You can obtain DIN from the View DIN e-Service.

If DIN is not available, please send us an email via myTax Mail.

* If the company does not meet the conditions for filing Form C-S, you can e-File or download Form C (Upload) (PDF format). If you are downloading the Form C for paper filing, the DIN must be entered in the DIN worksheet of the Form C. The DIN is the same whether you use Form C-S or Form C. 

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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