Form C

Compulsory e-Filling 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) will be made compulsory in a phased approach from Years of Assessment (YAs) 2018 to 2020 as follows:

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

The phased implementation will provide more time for smaller companies to modify their processes and ease into e-Filling.

New! The softcopy of Form C in PDF format, the e-Services for Online Form C and  Form C (Upload) for Year of Assessment (YA) 2018 are now available.

e-File Form C via mytax.iras.gov.sg and enjoy these benefits!

  • Auto-computation of certain fields that minimise filing errors
  • Get your estimated tax payable on-the-spot
  • iHelp for step-by-step guidance
  • Extra 15 days to e-File      

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

You can e-File Form C in two ways:

Modes How to e-File Suitable for 

Online Form C


Available now                    

Complete and file Form C online. Attach tax computation, financial statements, detailed profit & loss statement, other supporting documents and submit them to IRAS.  All companies/ tax agents 

Form C (Upload)


Available now

Download and complete Form C (PDF format) at your own time and convenience, in your local machine. No signature is required in Part V Declaration. When the Form C is completed and the file is saved in your local drive, upload it to myTax Portal and submit it together with tax computation, financial statements, detailed profit & loss statement and other supporting documents. Please upload the original Form C (PDF format). Do not upload a scanned or printed copy of Form C or Form C-S. Companies/ tax agents who need to show the completed Form C to obtain approval prior to submitting the Form C to IRAS


If your company cannot e-File Form C, please download the softcopy of Form C (Upload) (PDF format) below and follow the instructions for paper filing.

The particulars and requirements of Form C change from year to year. Please use the Form C of the respective YA to report your income.

To download Form C and Appendices, please click on the relevant YA below:

Please submit the Form C 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 submit Income Tax Return, but has now re-commenced business or is now in receipt of income, please complete and submit the Request for Income Tax Return (Form C-S/ C) and Notification of New Financial Year End (909KB) form by post or send us an email at myTax Mail.

To request the Form C for earlier YAs, please call us at 6356 7012 or email us at enfct@iras.gov.sg.

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 and filed as a hard copy. The DIN remains the same whether you file a paper Form C-S or Form C.

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

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

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

If you e-File Form C, either via online Form C or Form C (Upload), you do not need to input the DIN.

If the company meets the conditions for filing Form C-S, you can e-File Form C-S via mytax.iras.gov.sg or download the softcopy of Form C-S

Basic 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 you complete Form C. Please print and submit your tax computation and supporting schedules with your Form C.  

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