Form C-S and Form C in Singapore

  • Post category:Singapore

Singapore’s Inland Revenue Authority requires (IRAS) businesses to submit corporate tax returns annually. You can do this by submitting Form C or C-S of your tax return before the deadlines. It is also crucial to remember that you must still submit a company tax return even if the business is making losses.

This article will explain how the two forms differ, help you decide the one which applies to your firm, and take you through the process of declaring your company’s yearly income tax return.

Form C-S and Form C in Singapore


What is Form C-S?

Form C-S is a streamlined Corporate Income Tax Return for eligible small companies to report their revenue to the Inland Revenue Authority of Singapore (IRAS). Compared to Form C, Form C-S has fewer fields to fill out.

Form C-S includes:

  • A statement confirming the company’s eligibility for using the form
  • Details on tax adjustments
  • Information from the financial statements

If a company qualifies to file Form C-S, it is not necessary to submit its financial statements and tax computation along with the form. However, the company should still prepare these documents and be ready to present them if IRAS requests it.

Who is Eligible to File Form C-S?

Companies must meet the following criteria to file Form C-S:

  • The business must be set up in Singapore.
  • The business must have had annual revenues of S$5 million or less in the Year of Assessment.
  • The current corporate tax rate is 17%, which is applied to the company’s income.
  • There is no relief programme that the corporation is taking advantage of. These include investment allowance, asset allowance, overseas tax credit & deduction and group relief.

Companies are required to file Form C if they don’t meet these requirements. Additionally, a Form C-S Lite was developed by IRAS specifically for small businesses with yearly revenues of S$200,000 or less.

Necessary Document for Filing of Form C-S:

Only a declaration statement outlining the company’s eligibility as well as additional crucial tax and financial data must be filed with Form C-S. e-Filing is required by December 15th. 

Form C-S on paper must be submitted by 30 November. Even so, it is nevertheless advisable to establish and keep records of financial transactions, tax adjustments, and tax computations in case the IRAS requests them.

e-Filing of Tax Form C-S:

The e-Filing process is more convenient, allowing companies to submit their tax returns and supporting documents in a secure and timely manner.

  • To begin the e-Filing process, companies need to register for an e-filing account with IRAS. 
  • Once the account is set up, companies can log in and submit their form C-S, along with any supporting documents, such as financial statements and receipts. 
  • The e-Filing system also allows companies to track the status of their tax returns and make any necessary amendments.

In addition to the convenience of e-filing, companies can also expect faster processing times and reduced errors compared to paper filing. The e-filing system is designed to ensure that all information is accurate and complete, reducing the risk of errors and the need for additional follow-up.

Overall, e-Filing of Tax Form C-S in Singapore is an efficient and secure way for companies to file their taxes.

Note: Companies need to comply with the e-filing process to avoid penalties and to take advantage of the benefits that come with e-filing, such as a faster processing time and reduced errors.

What is Form C?

Form C is a tax form used in Singapore to report income and file taxes for individuals and sole proprietors. It is an annual requirement to file this form with the Inland Revenue Authority of Singapore (IRAS) to declare your income and pay taxes accordingly. It requires detailed information about your income, expenses and any other relevant information related to your tax return. 

It is important to file Form C by the deadline set by the IRAS to avoid any penalties. Failing to file this form may result in fines or penalties. It is mandatory for all the individuals or sole proprietors who earn any income in Singapore to file Form C.

Criteria for filing Form C:

All companies that are not eligible to file form C-S, or from C-S lite need to file form C. 

How to file Forms C-S or C?

Here’s a step-by-step guide to help you through the process:

  • Before you begin, make sure your company has an access code and that you are an “Approver”.
  • Keep the tax reference number and Corppass handy.
  • Log in to the myTax Portal, 
  • Choose Business Tax and log in using Corppass.
  • Put up the organization’s tax reference number.
  • Now click on Corporate Tax, and select File C-S/C.
  • Choose the financial year for which you’re filing and proceed to Form C-S or C.
  • Review the information on the confirmation page, save it, and click submit.
  • Remember to keep a copy of the e-filed form for your records.
  • Be aware of the deadline for filing Form C-S or Form C, and make sure to submit it on time to avoid penalties.

By following these simple steps, you’ll be able to complete your e-filing with ease and without any hassle.

When Should You File Form C Or Form C-S?

All firms in Singapore are mandated to submit their Form C or C-S through e-filing by November 30th of each financial year.


In conclusion, Singapore’s Inland Revenue Authority (IRAS) requires businesses to disclose their chargeable income by submitting Form C or C-S of their tax return before the deadlines. It’s important to note that even if the business is making losses, a company tax return must still be submitted.