Overview of Form C-S/ C

All companies carrying on a trade or business in Singapore need to report their income to IRAS annually by filing their Corporate Income Tax Return (Form C-S/ C).

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-S and Form C) will be made compulsory in a phased approach from 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 phased implementation will provide more time for smaller companies to modify their processes and ease into e-Filing.

Benefits of e-Filing

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Filing Due Dates

The annual filing due dates for Form C-S/ C is:

Method Due Date 
e-File 15 Dec 
 Paper File 30 Nov


Form C-S/ C

There are two types of Income Tax Return, Form C-S and Form C.

The Form C-S/ C is a declaration form for companies to declare their actual income. Companies must ensure that the form is correctly completed and gives a full and true account of the company's income.

Companies are still required to file the Form C-S/ C even if they are making losses.

Simplified Tax Filing with Form C-S

From Year of Assessment (YA) 2012, to simplify the filing procedure for small companies, IRAS introduced Form C-S - an Income Tax Return form shortened to three pages for qualifying small companies to report their income to IRAS.

Fewer Fields

Previously, small companies had to file Form C which has twice as many fields. Form C-S comprises:

  1. A declaration statement of the company's eligibility;
  2. Information on tax adjustments; and
  3. Information from the financial accounts.

No Need to Submit Documents unless Requested

Aside from having fewer fields to fill, qualifying small companies are also not required to submit financial statements and tax computation because essential tax information and financial information would have to be declared in the Form C-S. 

However, companies should prepare these financial statements and tax computation and submit them to IRAS upon request. 

Qualifying to File Form C-S

From YA 2017, companies will qualify to file Form C-S if they meet all of the following conditions:

  1. The company must be incorporated in Singapore;
  2. The company must have an annual revenue1 of $5 million2 or below
  3. The company only derives income taxable at the prevailing corporate tax rate of 17%3; and
  4. The company is not claiming any of the following in the YA:
    1. Carry-back of Current Year Capital Allowances/ Losses
    2. Group Relief
    3. Investment Allowance
    4. Foreign Tax Credit  and Tax Deducted at Source

Note: For YA 2019, if the value of a dormant company’s related party transactions disclosed in its financial statements for the financial period exceeds $15 million, it is required to submit Form C by
Form C (Upload) mode instead of Form C-S or Form C for Dormant Company. To determine if the value of the related party transactions exceeds $15 million, refer to Reporting of Related Party Transactions.

1 Revenue refers to the main income source of the company excluding separate source income, such as interest.
2 For YA 2016 and before, the revenue threshold for filing Form C-S is $1 million, i.e. the company must have an annual revenue of $1 million or below.
3 Form C-S should not be filed if the company derives income that is tax exempt or taxed at concessionary tax rates, such as where tax incentives are granted. The exceptions are where a company derives:
(I) One-tier tax exempt Singapore dividends, and/ or
(ii) Specified foreign-sourced income exempted from tax under S13(8) of the Income Tax Act.
In other words, a company can file Form C-S if it derives the above tax exempt income and meets conditions 1, 2 and 4. 

For more details on how to e-File Form C-S, please refer to Tips on e-Filing Form C-S.

Companies that do not meet the Form C-S qualifying conditions have to submit Form C together with financial statements, tax computation and supporting schedules.

Form C

If your company does not qualify to file Form C-S, you must file Form C.

To file Form C, you are required to submit your company's financial statements, tax computation and supporting schedules.

For more detail on how to e-File Form C, please refer to Tips on e-Filing Form C.

Getting the Form C-S/ C

IRAS will send companies either a Form C-S or Form C e-Filing notification letter by May of each year, starting from the second year following the year of incorporation. Companies are required to file their Income Tax Return by 30 Nov (for paper filing)/ 15 Dec (for e-Filing) in the year following the financial year.

New Companies

For information on filing of Form C-S or Form C by new companies, please refer to the Basic Guide for New Companies.

Signing Form C-S/ C

Any person authorised by the company can sign the Form C-S/ C. However, the director or principal officer of the company is still responsible for the company's tax affairs.

Failure to File Form C-S/ C

If the company does not file its Form C-S/ C by the due date, IRAS may issue a Notice of Assessment (NOA) based on an estimation of the company's income. If the company does not agree with IRAS' estimated assessment, please inform IRAS by filing a Notice of Objection within two months. Even if the company objects to the estimated assessment, tax on this assessment must still be paid within one month from the date of the NOA.

To find out more, please refer to Objecting to NOA.

Dormant Companies or Companies Closing Down

If your company is dormant or has ceased business operations, please refer to the details below on what you have to do:

  • Will I get an acknowledgement receipt if I hand deliver Form C-S/ C to IRAS at Revenue House?

    IRAS does not provide acknowledgement receipts for hand deliveries. e-File Form C-S/ C to get an instant acknowledgement.


  • Strongly Disagree
  • Strongly Agree

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