A Singapore company files an Estimated Chargeable Income within three months of its financial year end, files Form C-S, C-S (Lite) or C by 30 November, and must register for GST once taxable supplies exceed S$1 million. These guides explain which form applies, the exemptions available, GST registration and returns, and how to respond to IRAS.
Start with these guides
- Form C-S vs Form C-S (Lite) vs Form C: Which Singapore Tax Return Should Your Company File (2026)
- How to Plan Your First Corporate Tax Season as a New Company
- Startup Tax Exemption (SUTE) Singapore 2026: The First Three Years Explained
- YA 2026 CIT Rebate and Cash Grant: Who Qualifies, How Much and Worked Examples
- Common Corporate Tax Mistakes SMEs Make and How to Avoid IRAS Penalties
- How to Respond to an IRAS Query or Review Letter Professionally
- IRAS Court Summons for Unfiled Corporate Tax Returns: What Company Directors Face
- Withholding Tax (Section 45)
- Transfer Pricing Documentation in Singapore 2026: Who Must Prepare It and What It Must Contain
- How to Apply for GST Registration: Step‑by‑Step Process
- Pros and Cons of Voluntary GST Registration for SMEs in Singapore
- How to Prepare and File Your GST Returns Accurately and On Time
- GST Record‑Keeping Requirements and How to Stay Ready for an IRAS Audit
- GST Filing Services in Singapore: What a Quarterly GST Service Should Cost and Cover in the InvoiceNow Era
Our tax services
Tools: Form C-S eligibility checker, corporate tax calculator, GST registration checker. Official source: IRAS.
More tax and GST guides
Every other guide in this topic, newest first.
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- IRAS Advance Ruling 7/2026: Carrying Forward Unabsorbed Losses and Capital Allowances Through a Section 34C Amalgamation
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- Maritime Sector Incentive (MSI) in Singapore (2026): Tax Concessions for Shipping and Maritime Companies
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- Introduction to Corporate Tax in Singapore: Rates, Deadlines and Key Forms
- Foreign Tax Credit (FTC), pooling and limitations — Timeline and processing benchmarks
- Singapore holding company tax optimisation — Timeline and processing benchmarks
- How to Prepare for an ACRA or IRAS Compliance Review or Audit
- The Relationship Between Corporate Secretary, Accountant and Tax Agent in Singapore
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- Running an E-Commerce Business in Singapore (2026): Tax, GST & Compliance Guide
- Foreign Tax Credit (FTC), pooling and limitations — Complete 2026 guide
- Navigating Form IR21 and Tax Clearance in Singapore
- R&D Tax Deductions in Singapore: Section 14C, 14D and the Enterprise Innovation Scheme (2026)
- Singapore’s Global Minimum Tax (Pillar 2) 2026: What MNCs Must Do Before the June Deadline
- Running an E-Commerce Business in Singapore: Tax & Compliance Guide
- Incorporating an E‑commerce Business in Singapore: Licences, Tax and Logistics Basics
- GST Zero-Rating Rules for Export of Goods & Services
- Tax Season 2025: Key Updates and Pitfalls to Watch Out For
- Approved Refiner and Consolidator Scheme (ARCS) in Singapore
- Importing Precious Metals into Singapore: A Comprehensive Guide
- When Should Shipping Costs Be Separated from the Related Product Sale?
- Tightened UK Tax Rules May Benefit Financial Hubs Worldwide
- Singapore has enacted new legislation to implement additional corporate taxes
- What is a Tax Identification Number (TIN) in Singapore?
Talk to our team
For help with corporate tax and GST, email [email protected] or WhatsApp us at +65 8501 7133. Our office is at 151 Chin Swee Road, Manhattan House, #02-04A, Singapore 169876, open Monday to Friday, 10am to 6pm.