Corporate Tax Filing: Form C-S, Form C-S (Lite) & Form C

As a business owner in Singapore, it is essential to understand your tax obligations and ensure that you comply with the relevant regulations. One of the key tax requirements for businesses is corporate tax filing, which involves submitting either Form C-S, Form C-S (Lite), or Form C to the Inland Revenue Authority of Singapore (IRAS). Professional services providing GST Assisted Self-Help Kit (ASK) reviews can help businesses to ensure the accuracy of their GST submissions.

In this article, we will explore each form and what businesses need to know about filing them.

Form C-S

Form C-S is a simplified tax form that is designed for small Singapore-incorporated companies with an annual revenue of $5 million or less. The form is shorter and easier to complete than the full Form C. To qualify for Form C-S, companies must meet certain criteria. If a business earns income that is taxable under the prevailing Corporate Income Tax rate of 17% and is not claiming any of the following in the relevant Year of Assessment (YA): Carry-back of Current Year Capital Allowances/Losses, Investment Allowance, Group Relief, Foreign Tax Credit, and Tax Deducted at Source, then they are eligible to file their corporate tax using Form C-S (Lite).

For Form C-S, companies are not required to submit tax computations and financial statements. Once the form is completed, it can be submitted electronically to IRAS using the myTax Portal.

Form C-S (Lite)

Form C-S (Lite) is an even simpler version of Form C-S, designed for companies with an annual revenue of $200,000 or less. This form is ideal for small businesses that have minimal accounting records and can provide a simplified version of their financial statements. To be eligible for Form C-S (Lite), companies must meet certain criteria, such as not having more than ten employees and not having any foreign income.

Similar to Form C-S, companies do not need to provide detailed financial statements or tax computations. The form can be submitted electronically to IRAS using the myTax Portal, and there is no filing fee.

Form C

Form C is the full tax form that is required for companies that do not qualify for Form C-S or Form C-S (Lite). This form is intended for larger companies and is seven pages long and more detailed than the other types. It also requires companies to provide comprehensive financial statements, tax adjustments, and other information such as dividends paid and tax computations. Companies that are registered as investment holding companies or have foreign income are also required to file Form C.

To complete Form C, companies need to provide detailed information about their revenue, expenses, and capital allowances. They also need to declare any tax adjustments and provide financial statements that comply with the Singapore Financial Reporting Standards. Once the form is completed, it can be submitted electronically to IRAS using the myTax Portal.

How to file your corporate tax

All three forms can be filed electronically using the myTax Portal, which is a secure online platform provided by IRAS. To file your corporate tax, you need to log in to the myTax Portal using your company’s tax reference number and the SingPass or CorpPass authentication

Once you’re logged in, you can select the appropriate form based on your company’s eligibility and complete the required information. You can save the form as a draft if you need more time to complete it, and you can also make changes to a submitted form within 14 days of filing.


Corporate tax filing is an important requirement for businesses in Singapore, and it is essential to understand the different forms and deadlines to comply with the relevant regulations. Form C-S, Form C-S (Lite), and Form C are designed to cater to businesses of different sizes and complexities, and businesses should choose the appropriate form based on their eligibility. Businesses should also be aware of the common pitfalls to avoid when filing taxes. With proper planning and preparation, businesses can meet their tax obligations and focus on growing their business.

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*The above represents our views and opinions and does not necessarily reflect the position of any entities mentioned.