---
title: "Corporate Tax Filing Singapore: Forms and Dates | Aemorph"
url: https://aemorph.com/business-guides/compliance-tax-filing/
description: "Corporate tax filing in Singapore: ECI, then Form C-S, C-S (Lite) or Form C by 30 November, with worked tax figures and the cost of filing late."
publisher: Aemorph
publisher_entity: https://aemorph.com/entitymap.json#org_aemorph
entities: [concept_sg_corporate_tax_filing]
language: en-SG
updated: 2026-11-05
---

Business guides

# Corporate Tax Filing in Singapore: Which Form, Which Deadline, What Late Filing Costs

**Corporate tax filing in Singapore has two parts. Estimated Chargeable Income (ECI) is due within 3 months of the financial year end, and Form C-S, C-S (Lite) or C is due by 30 November. IRAS sets 30 November as the annual deadline, and 30 November 2026 falls 25 days after 5 November 2026. A Singapore-incorporated company with revenue of S$5 million or below and only 17%-taxed income qualifies for Form C-S.**

Written by [Kevin Dam](https://aemorph.com/about/), founder of Aemorph, who has practised SEO since 2010 and sits on the [Forbes Agency Council](https://councils.forbes.com/profile/Kevin-Dam-Global-Search-Architect-%7C-SEO-GEO-AEO-IMO-LLM-Visibility-Aemorph/4c8c7a38-1285-470d-8ea8-e517a310a00b). Aemorph is a [Google Partner](https://www.google.com/partners/agency?id=4441861842). [LinkedIn](https://www.linkedin.com/in/kevindam)

*Accurate as of 5 November 2026. Every figure, date and rule on this page was checked against its source on that date, and the page is rechecked monthly.*

---

## Each financial year end sets one ECI date and one annual return date

**A company files ECI within 3 months after its financial year end and its annual return by 30 November of the Year of Assessment.** The Year of Assessment (YA) is the year after the financial year ends. IRAS gives the example of a year ending 30 June 2024, which has an ECI deadline of 30 September 2024 and a YA 2025 return due 30 November 2025. The table applies the same rule to other year ends. This guide covers companies filing in Singapore. Tax residency tests, foreign-sourced income, deductions and withholding tax sit outside it.

| Financial year end | Year of Assessment | ECI due | Form C-S, C-S (Lite) or C due |
| --- | --- | --- | --- |
| 31 December 2025 | YA 2026 | 31 March 2026 | 30 November 2026 |
| 30 June 2026 | YA 2027 | 30 September 2026 | 30 November 2027 |
| 31 December 2026 | YA 2027 | 31 March 2027 | 30 November 2027 |
| 30 June 2027 | YA 2028 | 30 September 2027 | 30 November 2028 |

*Filing dates for four year ends, derived from the IRAS rule that YA 2025 covers financial years ending in 2024, checked 5 November 2026.*

*[Source: IRAS, November 2026](https://aemorph.com/sources/#iras-november-2026-a02a)*

*[Source: IRAS, May 2026](https://aemorph.com/sources/#iras-may-2026-e045)*

GST returns run on a separate quarterly calendar, which [GST in Singapore: When You Register, What You Charge and How You File](https://aemorph.com/business-guides/compliance-gst/) sets out.

### Does a dormant company still file?

**Yes, a dormant company files its tax return unless IRAS has granted a waiver.** ACRA states that every live company files an annual return even when it is inactive or dormant, and that a dormant company files tax returns unless IRAS has granted a waiver. IRAS lists a Form for Dormant Company among its annual return forms.

*[Source: ACRA, November 2026](https://aemorph.com/sources/#acra-november-2026-6d09)*

### When does a new company first file?

**A new company files for the Year of Assessment straight after its year of incorporation, even without a filing notification.** It uses IRAS's Request for Income Tax Return for Newly Incorporated Companies. A company whose first accounting period spans two Years of Assessment files both in one filing, using the later year and entering the full financial period.

## ECI sets the first tax estimate and the instalment plan

**A company with annual revenue of S$5 million or below and nil ECI does not file ECI, and IRAS needs no confirmation.** IRAS calls this an ECI waiver. Every other company files ECI through myTax Portal within 3 months after its year end, and e-filing has been compulsory since YA 2020. An earlier ECI starts a longer instalment plan, as the table shows for a 31 December year end.

| E-filing window (31 December year end) | Last e-filing day | Instalments | Monthly amount on S$12,000 estimated tax |
| --- | --- | --- | --- |
| Within 1 month | 26 January | 10 | S$12,000 ÷ 10 = S$1,200 |
| Within 2 months | 26 February | 8 | S$12,000 ÷ 8 = S$1,500 |
| Within 3 months | 26 March | 6 | S$12,000 ÷ 6 = S$2,000 |
| After 3 months | None | 0 | Full amount within 1 month of the Notice of Assessment |

*IRAS instalment tiers applied to an illustrative S$12,000 of estimated tax, checked 5 November 2026.*

*[Source: IRAS, November 2026](https://aemorph.com/sources/#iras-november-2026-d603)*

*[Source: IRAS, November 2026](https://aemorph.com/sources/#iras-november-2026-a02a)*

### Who gets instalments?

**Only Singapore-registered companies on GIRO pay by instalments.** A company without a GIRO arrangement for Corporate Tax applies at least 3 weeks before e-filing ECI. IRAS deducts instalments on the 6th of each month, and the minimum monthly deduction is S$50. If GIRO is not approved by the payment due date, the company pays the full estimated tax by that date.

## The annual return form follows tests on incorporation, revenue and income type

**Form C-S suits a Singapore-incorporated company with revenue of S$5 million or below and only 17%-taxed income, Form C-S (Lite) covers revenue of S$200,000 or below, and every other company files Form C.** A company that qualifies for Form C-S (Lite) still has the option of Form C-S or Form C. Non-Singapore-incorporated companies and Singapore branches of foreign companies do not file Form C-S.

| Form | Revenue limit | Income and claim conditions | Not eligible |
| --- | --- | --- | --- |
| Form C-S (Lite) | S$200,000 or below, from YA 2020 | Meets every Form C-S condition | A company outside the Form C-S conditions |
| Form C-S | S$5 million or below | Incorporated in Singapore, only income taxed at 17% | A company claiming carry-back of capital allowances or losses, group relief, investment allowance, or foreign tax credit and tax deducted at source |
| Form C | No limit | Any company outside the two conditions above | None |

*Eligibility for the three annual return forms, per the IRAS FAQs on Form C-S and Form C, checked 5 November 2026.*

*[Source: IRAS, November 2026](https://aemorph.com/sources/#iras-november-2026-478b)*

### What if revenue passes S$5 million?

**A company that filed Form C-S for YA 2025 files Form C-S for YA 2026 under an administrative concession, then files Form C for YA 2027 if its YA 2027 revenue also exceeds S$5 million.** The company still has to meet the other Form C-S conditions. IRAS states this in its Form C-S FAQs.

### Who in the company submits the return?

**An Approver authorised in Corppass for Corporate Tax (Filing and Applications) completes, approves and submits the return, while a Preparer completes it for the Approver only.** Directors remain responsible for accurate and timely filing even when a tax agent is engaged. IRAS shows the filing status 3 working days after submission.

### Which documents go with Form C?

**Form C goes with a tax computation, supporting schedules and the financial statements, uploaded as non-fillable PDF files.** The IRAS Form C FAQs, updated 15 May 2026, list the tax computation with a detailed profit and loss statement, and audited or unaudited financial statements. IRAS caps files at 4MB for the tax computation and financial statements and 2MB for the Section 19B declaration and R&D claim form. A status of "Received (ACRA)" means the full XBRL financial statements are already with ACRA.

### Does software filing extend the deadline?

**Yes, IRAS extends the due date by 15 days, from 30 November to 15 December, for Form C-S returns filed through accounting software, for YA 2023 to YA 2027.** IRAS states that businesses filing through the software route do not need to request the extension separately. Accounting software choices are compared in [Best Accounting Software in Singapore](https://aemorph.com/business-guides/accounting-software/).

*[Source: IRAS, November 2026](https://aemorph.com/sources/#iras-november-2026-7621)*

## The 17% rate, partial exemption and 50% rebate set the tax on chargeable income

**Tax on S$200,000 of chargeable income comes to S$8,287.50 after the partial tax exemption and the YA 2026 rebate, or S$6,375.00 under the start-up tax exemption.** IRAS states the prevailing rate as 17% for YA 2026. Companies that do not qualify for the start-up tax exemption (SUTE) receive the partial tax exemption (PTE) on the first S$200,000. IRAS states that the YA 2026 rebate is enhanced to 50% of tax payable, up to S$40,000.

| Step | Partial tax exemption (S$) | Start-up tax exemption (S$) | Working |
| --- | --- | --- | --- |
| Chargeable income | 200,000 | 200,000 | Illustrative figure |
| Exempt amount | 102,500 | 125,000 | PTE: 75% × 10,000 + 50% × 190,000 = 7,500 + 95,000. SUTE: 75% × 100,000 + 50% × 100,000 = 75,000 + 50,000 |
| Taxable amount | 97,500 | 75,000 | 200,000 minus the exempt amount |
| Tax at 17% | 16,575.00 | 12,750.00 | 97,500 × 17%; 75,000 × 17% |
| Rebate at 50% | 8,287.50 | 6,375.00 | 50% × tax at 17% |
| Tax payable | 8,287.50 | 6,375.00 | Tax at 17% minus rebate |

*A worked YA 2026 tax computation using IRAS exemption bands and the 50% rebate announced 7 April 2026, checked 5 November 2026.*

*[Source: IRAS, November 2026](https://aemorph.com/sources/#iras-november-2026-6057)*

*[Source: IRAS, November 2026](https://aemorph.com/sources/#iras-november-2026-6bf6)*

*[Source: MOF, April 2026](https://aemorph.com/sources/#mof-april-2026-4dad)*

*[Source: IRAS, November 2026](https://aemorph.com/sources/#iras-november-2026-7e9f)*

### Who receives the cash grant?

**An active company that made CPF contributions to at least one Singapore Citizen or Permanent Resident employee in 2025 receives a minimum S$2,000 cash grant, paid out of the rebate.** Shareholders who are also directors do not count as employees for this test. The MOF raised the minimum from S$1,500 to S$2,000 and the cap on total benefits from S$30,000 to S$40,000 on 7 April 2026. For a company that meets the local employee test, S$2,000 of the S$6,375 rebate in the SUTE column arrives as cash and the other S$4,375 offsets tax.

*[Source: Singapore Budget 2026, November 2026](https://aemorph.com/sources/#singapore-budget-2026-november-2026-6890)*

## A late return costs a composition offer of up to S$5,000 and ends in court if ignored

**Failing to file by the deadline is an offence under the Income Tax Act 1947, and IRAS offers composition of up to S$5,000, summons the director or issues an estimated assessment.** Payment on an assessment is due within 1 month of the Notice of Assessment (NOA) date. A company that files no return for 2 or more years faces a summons, and conviction carries a penalty of twice the assessed tax plus a fine of up to S$5,000.

| Event | IRAS response | Amount or rate | Worked on S$6,375 unpaid |
| --- | --- | --- | --- |
| Return not filed by 30 November | Composition offer, summons or estimated assessment | Composition up to S$5,000 | Not applicable |
| Tax unpaid after the NOA due date | Late payment penalty | 5% of unpaid tax | 5% × 6,375 = S$318.75 |
| Tax still unpaid 60 days after the 5% penalty | Additional penalty per completed month | 1% per month, up to 12% | 1% × 6,375 = S$63.75 a month, up to 12% × 6,375 = S$765.00 |
| No return for 2 or more years | Summons, then court | Twice the assessed tax plus a fine of up to S$5,000 | Not applicable |

*IRAS enforcement steps for late filing and late payment, with the penalty rates applied to S$6,375, checked 5 November 2026.*

*[Source: IRAS, November 2026](https://aemorph.com/sources/#iras-november-2026-a3a2)*

*[Source: IRAS, November 2026](https://aemorph.com/sources/#iras-november-2026-a02a)*

### When is the tax bill due?

**Payment is due 1 month from the date of the Notice of Assessment, so an NOA dated 2 June 2025 is due on 2 July 2025.** That date comes from IRAS's own example. A GIRO arrangement approved before the NOA due date avoids the 5% penalty, and IRAS processes new online GIRO applications in 3 working days and hardcopy forms in 3 weeks.

### Does objecting to an assessment stop penalties?

**No, filing an objection does not stop penalties, and IRAS requires payment of the tax assessed in the NOA.** IRAS refunds any excess if the assessment is revised. An appeal to waive a penalty needs full payment by the due date in the penalty notice and no waiver granted in the past two calendar years.

## Records stay on file for five years after the Year of Assessment

**Companies keep records for at least 5 years, so records for 1 July 2023 to 30 June 2024 stay until 31 December 2029.** That example comes from IRAS and applies even when the assessment is not finalised. Poor records let IRAS estimate income and disallow claims for expenses, capital allowances and GST input tax.

Companies and LLPs keep company records for 5 years after they are struck off, dissolved or wound up. IRAS accepts electronic records without prior approval when internal controls protect their integrity, completeness and accuracy. The wider obligations calendar sits in the [business compliance guide](https://aemorph.com/business-guides/compliance/).

*[Source: IRAS, November 2026](https://aemorph.com/sources/#iras-november-2026-d331)*

*General guidance as of 5 November 2026, not legal advice.*

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