Filing corporate tax for the first time can feel overwhelming, especially for newly incorporated SMEs navigating Singapore’s compliance calendar. But with a clear understanding of IRAS requirements, deadlines, and supporting documents, the process becomes much easier to manage.

This article explains what Form C and Form C-S are, who should file them, and provides a step-by-step checklist to help first-time filers stay compliant — with help from digital tools like ccMonet that simplify bookkeeping and tax readiness.

1. Corporate Tax Basics in Singapore

All companies registered in Singapore — including dormant ones — are required to file corporate income tax returns with the Inland Revenue Authority of Singapore (IRAS) every year.

Here’s what you need to know:

• Corporate tax rate: 17% on chargeable income.
• Basis period: Corresponds to your company’s financial year (e.g., FY2024 = YA2025).
• Filing period: IRAS assesses tax based on income earned in the preceding financial year.

💡 Example:
If your company’s financial year ended on 31 December 2024, you’ll be filing your YA2025 tax return by 15 December 2025 (if e-filing).

2. Understanding Form C vs Form C-S

Both Form C and Form C-S are used to file corporate income tax — the key difference lies in eligibility and complexity.

Form C-S (Simplified)

For smaller companies meeting all of these conditions:

• Incorporated in Singapore.
• Has annual revenue ≤ S$5 million.
• Income is taxable at 17% (no special rates or exemptions).
• Does not claim group relief, investment allowances, or carry-forward losses.

You’ll file Form C-S electronically through myTax Portal — no separate tax computation or financial statements need to be attached (though they must be kept for at least 5 years).

Form C

Required for larger or more complex companies that:

• Exceed the S$5 million revenue threshold, or
• Claim tax exemptions, capital allowances, or special deductions.

Form C filers must attach:

• Audited financial statements
• Tax computation schedules
• Supporting documents (e.g., capital allowance claims, prior year adjustments)

3. Corporate Tax Filing Deadlines

Filing Stage Deadline Description

‍Estimated Chargeable Income (ECI) Within 3 months after FYE Declare expected taxable income (even if nil).

‍Form C/C-S (Tax Return) 30 November (paper) / 15 December (e-filing) File actual income and tax computations for the YA.

‍Tax Payment As per IRAS Notice of AssessmentTypically payable in GIRO installments (up to 12 months).

Late or incorrect filings can trigger penalties of up to S$1,000, or even estimated assessments by IRAS.

4. The Essential Form C/C-S Filing Checklist

Here’s what every SME should prepare before filing:

A. Company Financials

• Finalized financial statements (Profit & Loss, Balance Sheet, and Notes).
• Trial balance and supporting ledgers.
• Bank reconciliations and expense summaries.

B. Tax Computations

• Calculation of chargeable income (revenue – deductible expenses).
• Adjustments for non-deductible expenses, e.g., entertainment or penalties.
• Claimable capital allowances, loss carry-forwards, and startup exemptions.

C. Supporting Schedules

• Depreciation and fixed asset schedules.
• Revenue breakdowns by activity.
• Related party transactions (if applicable).

D. Key Corporate Information

• Company UEN, registered address, and principal activity (SSIC).
• Directors’ particulars and shareholding structure.
• Confirmation of dormant or active status for the year.

💡 Tip: Keeping all records digital and reconciled throughout the year reduces filing time by up to 80%. With ccMonet, every invoice, expense, and payroll record is automatically categorized and ready for IRAS submissions.

5. Common Mistakes First-Time Filers Should Avoid

1. Missing the ECI filing — IRAS requires all companies to declare income within 3 months of FYE.
2. Filing under the wrong form (C vs C-S) — ensure eligibility for Form C-S before using it.
3. Incomplete or inaccurate tax adjustments — forgetting to exclude non-deductible expenses.
4. Failing to maintain proper records — financial statements and supporting documents must be retained for at least 5 years.
5. Late filing penalties — missing deadlines can lead to automatic assessments and fines.

6. Staying Tax-Ready with ccMonet

Preparing for tax season doesn’t have to be stressful. With ccMonet, SMEs can:

• Automate bookkeeping with AI-powered data extraction.
• Reconcile multi-currency transactions in real time.
• Generate year-end reports aligned with IRAS and ACRA formats.
• Collaborate directly with accounting experts for tax computation review.
• Access secure document storage for 5-year retention compliance.

By combining automation with expert oversight, ccMonet ensures your financial data stays accurate, audit-ready, and compliant — every month, not just at year-end.

7. Quick Summary: First-Time Corporate Tax Filing Steps

1. Determine your YA (Year of Assessment) based on your financial year end.
2. File ECI within 3 months after FYE.
3. Prepare your financial statements and tax computations.
4. Submit Form C-S (or Form C) via myTax Portal by 15 December.
5. Retain all records for at least 5 years.

Conclusion

Your first corporate tax filing marks an important compliance milestone — one that sets the tone for your company’s financial discipline and credibility.

By planning ahead, organizing records digitally, and leveraging automation through ccMonet, SMEs can transform tax filing from a stressful year-end task into a smooth, well-structured process.

👉 Get your books and tax-ready reports organized with ccMonet — visit ccMonet.ai to learn how our AI bookkeeping and expert review system helps you stay compliant from day one.

‍