This post is also available in: 简体中文 (Chinese (Simplified))

IRAS Document Identification Number (DIN)

IRAS Document Identification Number (DIN) Are you familiar with IRAS’s Document Identification Number? Referred to as DIN for short, the IRAS generates this unique number for the purpose of identifying each income tax return which is issued. A company’s DIN would be available in Form C-S/C for a specific YA (Year of Assessment) period.

A company’s DIN is unique and under no circumstances should this number be used by another company, or for another YA period by the same company. A company would require a DIN only when downloading a copy of Form C-S/C, and when they are submitting the paper documentation to IRAS. A DIN may be obtained from IRAS’s website under the View DIN e-service option.


Why Do I Need a DIN?

Companies are required to have a DIN if they file a paper Form C-S/C which has been downloaded from the IRAS website or via their designated tax agent’s software. A company is required to quote their DIN numbers on their Form C-S/C for easier reference.


What Is Form C-S/C?

Form C-S is a simplified version of a 3-page income tax return form, which is used by companies to report their income to IRAS. Companies who quality for Form C-S may opt to use this instead of Form C to report their income.

The e-File version of Form C-S is easily available on the website, and companies will find this option very convenient because of the following benefits:

  • It provides instantaneous estimates of tax payable
  • The iHelp section provides step-by-step guidance to complete the process
  • Auto-computation of certain fields is available to keep errors to a minimum
  • Companies get an extra 15 days to do their e-Filing


Where Would I Get a DIN From?

Companies may easily obtain the DIN through the e-Service View DIN option on IRAS’s website. This service is easily accessible and there is no need for any prior registration in order to be able to access this service.


Is There an Instance Where a Company May Not Be Able to Obtain Its DIN?

Yes, there may be instances when this may happen. Some examples of these situations include:

  • A company is newly incorporated and still within its first two years of incorporation. In this case, IRAS would only issue the Form C-S/C e-filing notification after the two-year period is over. The two-year timeframe starts from the company’s year of incorporation.
  • The company in question has been granted with a waiver to submit their income tax return.
  • The company has already filed its Form C-S/C for that YA period. Companies should check the status of their corporate tax return to be sure.


When Should I Submit My Form C-S/C?

All companies in Singapore are encouraged to start the e-Filing process for their Corporate Tax Return (or Form C-S/C). Companies would receive a notification letter which will be delivered to the company’s registered address.