Navigating Singapore’s corporate tax filing requirements is a crucial aspect of doing business. The Inalnd Revenue Authority of Singapore (IRAS) offers three different corporate income tax returns-FormC-S(Lite), Form C-S, and Form C – to cater to the varying complexities and sizes of businesss. All companies are required to e-file their returns by the deadline of 30 November 2025 for the Year of Assessment (YA) 2025.
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Here’s a detailed guide to help you to determine the right form for your company and how to file it.
Choosing the Right Form: Eligibility Criteria
The first step is to identify which form your company is eligible to file. This is primarily based on your company’s revenue and specific tax claims.
| Form Type | Annual Revenue | Key Eligibility Conditions |
|---|---|---|
| Form C-S (Lite) | S$200,000 or below | - Company incorporated in Singapore - Derives income taxable only at the prevailing 17% corporate tax rate - Not claiming carry back of capital allowances/losses, group relief, investment allowance, foreign tax credit, or tax dedicted at source |
| Form C-S | S$5 million or below | |
| Form C | Any amount | - This is the standard, most detailed form for all companies that do not qualify for Form C-S/Form C-S (Lite) - Companies that need to make complex tax claims must use this form |
Even if your company is makking losses or had no income, you are still required to file one of these forms, unless your company is dormant and has been granted a waiver by IRAS.
Essential Pre-Filing Preparations
Before you begin the e-filing process on the myTax Portal, ensure you have the following ready:
For all Forms:
- Corpass Authorisation: The individual filing the return (eg. Director or a Tax agent) must be authorised as an “Approver” for “Corporate Tax (Filing and Applications)” in Corppass.
- Singpass: To log in to the myTax Portal/
- Company’s Unique Entity Number (UEN)
- Financial Statements : Prepare the company’s audited or unaudited financial statements (also known as accounts).
- Tax Computation and Supporting Schedules: A detailed tax computation is necessary to arrive the chargeable income.
- Details of exempt/deductible income.
Key Difference in Documentation Submission:
- Form C-S (Lite) and Form C-S: You are not required to submit your financial statements and tax computation with the form. However, you must have them prepared and ready for submission upon IRAS’s request.
- Form C: You must submit your financial statements, tax computation, and all relevant supporting schedules along with the form.
Step-by-Step Guide to e-Filing
The e-filing process for all three forms is done through IRAS myTax Portal and follows a similar flow.
Step 1: Log in to myTax Portal
- Visit the mytax portal
- Log in using your Singpass and the company’s UEN.
Step 2: Navigate to Corporate Tax Filing
- From the main menu, select Corporate Tax.
- Click on File Form C-S/C
Step 3: Initiate Filing and Select Form Type
- You will see summary of your company’s filing status. Click on E-File to begin.
- You will be prompted to enter your company’s revenue for the financial year.
- Based on the revenue entered and your answers to a few qualifiying questions, the system will recommend the appropriate form (Form C-S(Lite), Form C-S, or Form C).
Step 4: Complete the Online Form
- For Form C-S(Lite): This is the simplest form with only six essential fields to complete, focusing on basic income and tax adjustments.
- For Form C-S: This form requires more detailed information from your financial statements and tax computation, including a breakdown of tax adjustments.
- For Form C: This is the most comprehensive form, requiring detailed information on various tax matters, including capital allowances, loss carry-fowrads and any special claims. You will also need to attach the required supporting documents.
Step 5: Review, Declare, and Submit
- Carefully review all the information you have entered. The portal has an auto-save feature, so your draft will be saved as you move between pages.
- Complete the declaration section, confirming that the information provided is true and complete. This must be done by company director or an authorised person.
- Click Submit. An instant acknowledgement will be displayed upon successful submission. It is advisable to save a PDF copy of this acknowledgement page for your records.
By understanding the specific requirements for each form and preparing the necessary documentation in advance, you can ensure a smooth and compliant corporate tax filing process with IRAS.
What Happens After Submission?
1. Notice of Assessment (NOA): IRAS will process your return and send you a NOA, typically within 14 days to few months after filing. This is your official tax bill.
2. Payment: The NOA will state the amount of tax payable and the payment due date. You can pay via various methods (GIRO, AXS,Enets, bank transfer).
Important Considerations & Best Practices
- Deadline is Key: The filing deadline is 30 November. Late filling result in penalties and possibly a higher estimated tax bill from IRAS.
- Amending a Submitted Return: If you discover an error after submission, you must inform IRAS immediately. You can file an amendment through the “Object to Assessment” function in myTax Portal or by writing to IRAS. Do not wait for them to find it.
- Seek Professional Help: If you are not familiar with the process and regulations or complex filing, engage a qualified accountant or tax agent. The cost is often worth avoiding errors and penalties. B6 is here to handle the complexity for you. Please connect with us to explore more.