Corporate Tax Deadline in Singapore

If you're running a company in Singapore, corporate tax runs on a completely separate clock from personal income tax. It's tied to your company's Financial Year End, not the calendar year. And unlike personal taxes, the consequences of missing a corporate deadline land on the company and its directors.

This guide covers every corporate tax filing deadline for 2026, which forms to file, what happens if you miss a date, and how the exemptions work.

In this guide:

• Key deadlines and dates for 2026

• Which tax return form applies to your company

• How exemptions reduce your actual tax bill

• Penalties for late filing and non-payment

Key Takeaways

1. The corporate income tax return (Form C-S / C-S Lite / C) is due 30 November 2026 for all Singapore companies. ECI is a separate, earlier filing due within 3 months of your Financial Year End.

2. Every Singapore-incorporated company must file a corporate income tax return, including dormant companies and those with zero revenue.

3. Budget 2026 introduced a 40% Corporate Income Tax Rebate on tax payable for YA 2026, capped at S$30,000, applied automatically by IRAS, with no separate claim needed.

Who Must File Corporate Income Tax in Singapore

Under the Income Tax Act 1947, every company incorporated or registered in Singapore must file a corporate income tax return, regardless of profit, revenue, or trading status.

This includes:

• Active Pte Ltd companies of any size

• Dormant companies without a formal IRAS waiver

• Foreign companies with a Singapore-registered presence

• Companies in their first year of operations, even with zero revenue

Directors are personally accountable for ensuring timely filing. Engaging an external accountant or corporate service provider does not transfer this legal obligation. IRAS issues enforcement notices directly to directors when company returns are overdue.

Key Singapore Tax Filing Deadlines 2026

Missing a tax deadline in Singapore can result in penalties and late filing fees. Below is a complete breakdown of all key corporate tax filing obligations for 2026, organised by filing type.

Corporate Income Tax Deadlines

There are two corporate income tax submissions to note:

• Estimated Chargeable Income (ECI) must be filed within 3 months of your company's Financial Year End

• Corporate Income Tax Return (Form C / C-S / C-S Lite) is due on 30 November 2026 for all Singapore-incorporated companies, regardless of Financial Year End or revenue level

Employment Income Submission Deadline

Employers participating in the Auto-Inclusion Scheme (AIS) must submit their employees' employment income and commission records to IRAS by 1 March 2026.

GST Filing Deadlines (Quarterly)

If your company is GST-registered on a quarterly filing cycle, you are required to file 4 GST returns per year, one for each quarter, due within 1 month after the quarter ends. For companies filing throughout 2026, the deadlines are as follows: 
 

Filing	Quarter Covered	Deadline
GST Return (Q4 2025)	Oct - Dec 2025	31 Jan 2026
GST Return (Q1 2026)	Jan - Mar 2026	30 Apr 2026
GST Return (Q2 2026)	Apr - Jun 2026	31 Jul 2026
GST Return (Q3 2026)	Jul - Sep 2026	31 Oct 2026

Filing for Q4 2026 (Oct – Dec 2026)? That deadline falls on 31 Jan 2027.

ACRA Deadlines to File Alongside Your Tax Returns

IRAS and ACRA are separate regulators with separate penalties. Two ACRA dates run in parallel with your tax calendar:

• Annual General Meeting (AGM): within 6 months of your Financial Year End

• Annual Return via BizFile+: within 7 months of your Financial Year End

ACRA issues formal red notices as pre-warnings before escalating to summonses. Directors face penalties under the Companies Act for late Annual Returns, independent of any IRAS exposure.

Deadline tracking handled for you, automatically Swiftly's corporate secretary service logs every IRAS and ACRA filing date and sends reminders via WhatsApp and email.

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ECI vs Form C: Understanding the Two Core Filings

ECI and your annual tax return are two distinct filings that serve different purposes.

Estimated Chargeable Income (ECI)

Estimated Chargeable Income (ECI) is a preliminary estimate of your company's taxable profits, filed within 3 months of your Financial Year End.

IRAS uses it to compute your provisional tax. If you're on GIRO, it also sets up interest-free instalment payments of up to 10 months.

It's worth filing on time even when cash flow is comfortable. Miss the ECI deadline and you lose the GIRO instalment benefit entirely.

ECI exemption conditions: Your company is exempt from filing ECI if both of the following apply:

• Annual revenue is S$5 million or below

• ECI for the Year of Assessment is nil

One important nuance: ECI is based on taxable income after tax adjustments, not accounting profit. A company showing zero accounting profit can still have a positive ECI if non-deductible expenses are added back. When in doubt, check with your accountant before skipping the filing.

Corporate Income Tax Return — Form C-S, C-S Lite, or Form C

All Singapore companies file one of three forms by 30 November, determined by annual revenue:

• Form C-S Lite: annual revenue S$200,000 or below. Six main fields, no financial statements required.

• Form C-S: annual revenue S$5 million or below. No financial statement submission needed, though a tax computation is required.

• Form C: all other companies. Full financial statements and tax computation submitted to IRAS.

Forms C-S and C-S Lite don't require financial statements to be submitted to IRAS.

That said, you still need to prepare and retain them. IRAS can request your records at any point after filing.

Filing is done via the IRAS MyTax Portal using your company's CorpPass login.

Note: If you file Form C-S via IRAS's Seamless Filing From Software (SFFS), you automatically receive a 15-day extension to 15 December. This does not apply to Form C.

Singapore Corporate Tax Rate and Exemptions

Singapore's corporate income tax rate is a flat 17% on chargeable income.

Most SMEs pay significantly less once IRAS exemptions are applied, particularly in the first 3 years of operation.

Start-Up Tax Exemption — First 3 Years

Newly incorporated Singapore-resident companies are entitled to partial tax exemption for their first three consecutive Years of Assessment:

• First S$100,000 of chargeable income: 75% exempt, effective rate of approximately 4.25%

• Next S$100,000 of chargeable income: 50% exempt, effective rate of approximately 8.5%

• Above S$200,000: standard 17% rate applies

To qualify, the company must be tax-resident and incorporated in Singapore.

It must also have no more than 20 shareholders, with at least one individual holding a minimum 10% stake. Investment holding companies and property developers are excluded.

YA 2026 Corporate Income Tax Rebate

As announced in Budget 2026, all companies receive a 40% Corporate Income Tax Rebate on tax payable for YA 2026, capped at S$30,000.

The rebate is applied automatically when IRAS computes your assessment. No application is required.

Make sure every exemption is applied to your assessment Swiftly's accounting team handles your full tax computation, ensuring start-up and partial exemptions are correctly applied to your assessment.

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Penalties for Late Filing and Non-Payment

IRAS treats late payment and non-filing as separate offences, each with its own penalties and director-level consequences.

Late Payment

Once a Notice of Assessment (NOA), IRAS's formal statement of your company's tax liability is issued, tax must be paid within 30 days.

If payment is not made:

• Estimated assessment: A 5% late payment penalty is imposed immediately on the outstanding amount

• Monthly additions: An additional 1% per month is added for every completed month the tax remains unpaid

• Maximum surcharge: The combined penalty reaches up to 17% of unpaid tax (5% initial + up to 12% monthly additions)

Non-Filing

Missing the 30 November Form C deadline triggers a different escalation:

• Estimated assessment: IRAS raises an assessment based on prior years. Payment is due within one month, even if you dispute the figure.

• Composition fine: Fines of up to S$5,000 under the Income Tax Act.

• Section 65B(3) notice: IRAS can require directors to provide information or documents related to the return.

• Court summons: Persistent non-compliance leads to legal action and director-level enforcement. The legal obligation to file cannot be delegated.

Missed the deadline? Here's what to do

Act quickly to minimise penalties:

1. File immediately via the IRAS MyTax Portal and settle any outstanding tax

2. Respond to all IRAS notices promptly. Do not ignore them

3. Apply for a GIRO payment plan if cash flow is tight

4. Engage a tax agent if you need help correcting past returns or responding to enforcement letters

Never Miss a Corporate Tax Deadline Again

Corporate tax compliance in Singapore involves more moving parts than most directors realise. ECI, Form C, ACRA filings, and GST returns each run on their own schedule.

Swiftly is an ACRA-licensed corporate service provider that handles it all in one place: accounting and tax filing, company secretarial services, and incorporation. Automated deadline reminders, transparent pricing, and a Singapore-based team of certified accountants behind every engagement.

Frequently Asked Questions

What is the corporate tax filing deadline in Singapore for 2026?

The Corporate Income Tax Return (Form C-S / C-S Lite / C) must be filed by 30 November 2026 for all Singapore companies.

ECI is due within 3 months of your Financial Year End. 31 March 2026 for a December FYE, 30 June 2026 for a March FYE, and so on.

Does my company need to file if it made no profit or was dormant?

Yes. Filing is mandatory regardless of profitability or trading status.

The only exception is a formal IRAS dormancy waiver, which must be applied for in advance. Without one, the obligation stands.

When will I receive my Notice of Assessment?

IRAS typically issues the Notice of Assessment (NOA) by 31 May of the year following your filing.

If you disagree with the assessment, you have 2 months from the NOA date to file an objection with IRAS.

What happens if I miss the 30 November deadline?

IRAS will raise an estimated assessment based on prior years, which may exceed your actual liability. Payment is still due within one month.

Fines of up to S$5,000 apply, and repeated non-compliance results in court summonses and director-level enforcement action.

How does GIRO affect my ECI filing and tax payment?

Companies on GIRO that file ECI by the 26th of the qualifying month. For example, 26 March for a December FYE, can spread their tax payment across up to 10 interest-free monthly instalments.

GIRO should be set up at least 3 weeks before you plan to file ECI to ensure the instalment plan is activated in time.

Can a company secretary help with corporate tax filing?

Company secretarial services cover ACRA obligations — Annual Returns, AGMs, and statutory registers. Corporate tax filing is a separate IRAS obligation handled by an accountant or tax agent.

Swiftly provides both under one roof, removing the coordination gap that typically exists when two separate providers are managing different parts of your compliance calendar.