Guidance on Completing Form C-S/ C

Guides to complete Form C-S/ C online or via paper filing.

Go paperless! All companies can e-File Form C-S/ C!

Before Completing Form C-S/ C

All companies need to prepare the following before completing the Income Tax Return (Form C-S/ C):

  • the audited/ unaudited financial statements,
  • tax computation and supporting schedules, and
  • other claim forms

For more details, please refer to Documents to Prepare when Filing Form C-S/ C.

New! If your company’s functional currency is not in “Singapore Dollar”, you have to inform IRAS by logging in to and updating it via the "Update Corporate Profile/ Contact Details" e-Service. You may refer to the following user guides for more information:

• “Update Corporate Profile/ Contact Details” User Guide (company) (1.04MB)
• “Update Corporate Profile/ Contact Details” User Guide (tax agent) (1.10MB)

e-Services Authorisation System for Corporate Tax Matters

You must first authorise your staff or tax agent for 'Corporate Tax Matters' in the e-Services Authorisation System (EASY) before they can log in to e-File Form C-S/ C on behalf of the company.

If a tax agent is e-Filing on your company’s behalf, please note that you can only authorise one tax agent for a particular tax type (e.g. corporate tax or GST, etc.) in EASY at any one time. Hence, if you have changed your corporate tax agent, you will have to remove your authorisation for your old tax agent and authorise the new one in EASY. Please read the EASY user guide (210KB) on how to View/Edit/Delete Records for third party and the user guide (138KB) on how to authorise your third party.

Filing Form C-S

Filing Form C

e-Filing of Form C

You can e-File Form C in two ways:

ModesHow to e-FileSuitable 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


Online Form C:

Form C (Upload):

Paper Filing of Form C


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