Annual Tax Filing with IRAS for Singapore Companies

All Singapore-incorporated companies must comply with tax filing requirements set by the Inland Revenue Authority of Singapore (IRAS). This involves two main filings each year: 

1. Estimated Chargeable Income (ECI) – Filed within 3 months after the financial year-end (FYE) 

2. Corporate Income Tax Return (Form C-S / C-S Lite / C) – Filed by 30 November each year 

Failure to meet tax filing deadlines may result in penalties, fines, or prosecution by IRAS. 

1. Estimated Chargeable Income (ECI) 

What is ECI? 

ECI is an estimate of the company’s taxable profits (after deducting allowable expenses) for the financial year. Companies must file their ECI within 3 months from the financial year-end (FYE) unless they qualify for an exemption. 

Who Must File ECI? 

✅ All companies must file ECI, except those that meet both of these criteria: 

• Annual revenue is ≤ S$5 million 

• ECI (taxable profits) is zero 

ECI Filing Deadline 

Financial Year-End (FYE)	ECI Filing Deadline
31 March 2025	30 June 2025
30 June 2025	30 September 2025
31 December 2025	31 March 2026

How to File ECI? 

✅ File online via myTax Portal on the IRAS website 

✅ Companies can revise their ECI within 3 months after submission 

Tax Benefits of Early ECI Filing 

• If ECI is filed within 1 month from FYE, companies can enjoy tax installment payments 

• Late filing may lead to fines or enforcement actions 

2. Corporate Income Tax Return (Form C-S / C-S Lite / C) 

What is the Corporate Tax Return? 

This is the final tax declaration of a company’s taxable income, including deductions, capital allowances, and reliefs. 

Filing Deadline: 30 November each year 

Types of Corporate Tax Returns 

Form Type	Who Can Use It?	Criteria
Form C-S Lite	Small companies with simple tax matters	Revenue ≤ S$200,000, simplified declaration
Form C-S	Companies with revenue ≤ S$5 million	Must qualify for simplified reporting
Form C	Companies with revenue > S$5 million	Full tax computation & financial statements required

Filing Process 

1️⃣ Prepare Financial Statements (Audited or Unaudited) 

2️⃣ Prepare Tax Computation (Adjust net profit to taxable profit) 

3️⃣ Submit Form C-S / C-S Lite / C via myTax Portal 

4️⃣ Pay Corporate Income Tax (17% on taxable profits) 

Penalties for Late Filing 

❌ First-time late filing → Reminder notice from IRAS

❌ Failure to file by the due date → S$300 - S$1,000 fine 

❌ Repeated non-compliance → IRAS may issue a Summons 

3. Corporate Tax Rate & Tax Incentives 

• Corporate Tax Rate: 17% on chargeable income 

• Partial Tax Exemption for Startups: 

• First S$100,000 of chargeable income → 75% exempt (for first 3 years) 

• Next S$100,000 → 50% exempt 

• Tax Exemptions for SMEs: 

• Partial tax exemption on chargeable income up to S$200,000 

• Business Expense Deductions: 

• Companies can claim deductions for business expenses, capital allowances, and R&D expenses. 

4. Other Tax Compliance Obligations 

✅ Goods & Services Tax (GST): 

• Companies with revenue ≥ S$1 million must register for GST and file quarterly GST returns. 

✅ Withholding Tax: 

• Applies to payments to non-resident individuals or entities (e.g., interest, royalties, service fees). 

✅ Transfer Pricing Documentation: 

• Required for related-party transactions exceeding S$10 million. 

5. Summary of Corporate Tax Filing Deadlines 

Requirement	Deadline
ECI Filing	Within 3 months after FYE
Corporate Tax Return (Form C-S / C-S Lite / C)	30 November each year
GST Filing (if applicable)	Every quarter

Conclusion 

Staying compliant with IRAS tax filing obligations ensures that businesses avoid penalties and remain in good standing. Companies should: 

✅ Keep accurate financial records ✅ File ECI within 3 months after FYE (if required) 

✅ Submit Form C-S / C-S Lite / C by 30 November 

✅ Consider tax exemptions & reliefs to reduce tax liabilities