Singapore Corporate Tax 2026/2027: ECI & Forms
Singapore corporate tax 2026/2027: Learn ECI deadlines, Form C-S, Form C-S (Lite), Form C, IRAS eligibility rules and filing requirements for all companies.
SINGAPORE
Example — Financial Year Ended 31 December 2026
A company with FYE 31 December 2026 generally has the following obligations:
ECI filing deadline: 31 March 2027
Relevant Year of Assessment: YA 2027
Annual corporate tax return deadline: 30 November 2027
ECI is an estimate submitted earlier in the tax reporting cycle. The annual Corporate Income Tax Return reports the company's actual tax position.
When Is a Company Exempt from Filing ECI?
IRAS generally waives ECI filing when both of the following conditions are satisfied:
Annual revenue does not exceed S$5 million for the financial year.
ECI for the relevant Year of Assessment is nil.
The nil ECI amount must be determined before deducting tax-exempt amounts under the partial tax exemption or start-up tax exemption schemes.
For the ECI filing waiver, IRAS generally considers revenue from the company's principal income-generating activity. Separate-source income, such as interest, dividends or rental income unrelated to the principal activity, may be excluded from this revenue measure. For an investment holding company, investment income generally forms part of its revenue.
Practical Examples
Example A: Annual revenue of S$1 million and ECI of S$50,000.
ECI filing is required because the company's ECI is not nil.
Example B: Annual revenue of S$4 million and nil ECI.
The company generally qualifies for the ECI filing waiver.
Example C: Annual revenue of S$8 million and nil ECI.
ECI filing is still required because annual revenue exceeds S$5 million.
Common mistake: Assuming that a loss-making company never needs to submit ECI. The annual revenue condition must also be considered.
3. What Are Form C-S, Form C-S (Lite) and Form C?
After the relevant financial year, companies must assess which corporate income tax return applies to them.
Form C-S (Lite) — Very Small Companies
Form C-S (Lite) is a simplified return for eligible companies with annual revenue of S$200,000 or below.
The company must first satisfy the qualifying conditions for Form C-S.
It generally requires only six essential fields, making it suitable for companies with straightforward tax matters.
Form C-S — Qualifying Small Companies
Form C-S is available to companies that:
Are incorporated in Singapore.
Have annual revenue of S$5 million or below.
Derive income taxable at the prevailing 17% corporate income tax rate, subject to specified exceptions.
Do not claim certain tax reliefs or credits that disqualify the use of Form C-S.
Examples of disqualifying claims include group relief, investment allowance, carry-back of current-year capital allowances or losses, and specified foreign tax credits or tax deducted at source.
Companies filing Form C-S generally do not need to submit their financial statements and tax computations with the return.
However, they must still prepare these documents and retain them for submission if IRAS requests them.
Form C — Companies Requiring Full Tax Reporting
Companies that do not qualify for Form C-S or Form C-S (Lite) must file Form C.
Companies filing Form C generally must submit their tax computation and applicable supporting documents. Financial statements are also generally required, although IRAS may not require resubmission where a full set has already been filed with ACRA in XBRL format.
Important Consideration
A company with revenue below S$5 million does not automatically qualify for Form C-S.
Eligibility depends on the nature of its income and relevant tax claims, not solely on its revenue.
Last reviewed: 18 October 2026
Singapore companies must comply with annual corporate income tax requirements administered by the Inland Revenue Authority of Singapore (IRAS). These obligations commonly involve two separate filings: Estimated Chargeable Income (ECI) and the annual Corporate Income Tax Return.
However, not every company files the same return. Depending on its revenue, income sources and tax claims, a company may qualify for Form C-S (Lite), Form C-S or be required to file Form C.
This guide explains Singapore corporate tax filing requirements for 2026 and 2027, including important deadlines, available exemptions and practical compliance considerations.
Key Takeaways
Corporate tax rate: Singapore's prevailing corporate income tax rate is 17% of chargeable income.
ECI deadline: Generally within three months after the financial year end.
ECI waiver: Available when annual revenue is S$5 million or below and ECI is nil, subject to the applicable rules.
Form C-S (Lite): For companies qualifying for Form C-S with annual revenue of S$200,000 or below.
Form C-S: For qualifying Singapore-incorporated companies with annual revenue of S$5 million or below.
Form C: Required for companies that do not qualify for the simplified forms.
Annual tax return deadline: Generally 30 November of the relevant Year of Assessment.
1. Understanding Singapore Corporate Income Tax
Singapore companies are generally taxed at 17% on chargeable income.
Chargeable income is not necessarily the same as accounting profit. A company must review its financial statements and make the relevant tax adjustments.
These may include:
Adding back non-deductible expenses.
Deducting allowable business expenditure.
Claiming applicable capital allowances.
Considering qualifying tax exemptions and reliefs.
Reviewing foreign-sourced income and withholding tax implications.
Evaluating related-party and transfer pricing arrangements.
The final corporate tax payable depends on the company's chargeable income, applicable exemptions, credits and any tax rebate available for the relevant Year of Assessment.
Financial Year End vs Year of Assessment
Singapore uses a Year of Assessment (YA) system.
Generally, the financial year ending in 2025 forms the basis for YA 2026, while the financial year ending in 2026 forms the basis for YA 2027.
For example, a company with a financial year ending 31 December 2025 generally reports that financial period under YA 2026.
Understanding this distinction is essential when determining filing deadlines.
2. What Is Estimated Chargeable Income (ECI)?
ECI is an estimate of a company's taxable profits for a particular Year of Assessment.
Companies generally must submit ECI to IRAS within three months after the end of their financial year unless they qualify for the filing waiver or fall within a specific exemption category.
4. Singapore Corporate Tax Filing Deadlines for 2026 and 2027
The two main filing deadlines are:
ECI: Generally within three months after the financial year end, unless exempt.
Form C-S, Form C-S (Lite) or Form C: Generally by 30 November of the relevant Year of Assessment.
For a company with FYE 31 December 2025, the relevant Year of Assessment is generally YA 2026.
Its ECI deadline would generally be 31 March 2026, while its annual corporate income tax return would be due on 30 November 2026.
For a company with FYE 31 December 2026, the relevant Year of Assessment is generally YA 2027. Its ECI and annual return deadlines would generally fall on 31 March 2027 and 30 November 2027 respectively.
Companies with different financial year ends must calculate their deadlines accordingly.
5. Tax Exemption for New Start-Up Companies
Singapore provides a tax exemption scheme for qualifying newly incorporated companies during their first three consecutive Years of Assessment.
For YA 2020 onwards, the exemption generally provides:
75% exemption on the first S$100,000 of normal chargeable income.
50% exemption on the next S$100,000 of normal chargeable income.
The maximum amount of income exempted under the scheme is S$125,000 for each qualifying Year of Assessment.
To qualify, a company must be incorporated in Singapore and be a Singapore tax resident for the relevant Year of Assessment.
Its total share capital must also be beneficially held directly by no more than 20 shareholders throughout the relevant basis period. In addition, either all shareholders must be individuals, or at least one individual shareholder must hold at least 10% of the company's issued ordinary shares.
Foreign ownership does not automatically disqualify a company, but the shareholding structure and other qualifying conditions must be assessed.
Companies whose principal activity is investment holding, and certain property development companies, are excluded from the start-up exemption scheme.
They may instead qualify for the partial tax exemption scheme.
Important: The first three consecutive Years of Assessment are relevant, even where the company makes losses or has no chargeable income in one of those years.
6. Partial Tax Exemption for Companies
Companies that do not qualify for the new start-up tax exemption scheme may be eligible for the partial tax exemption scheme.
For YA 2020 onwards, the general partial exemption is:
75% exemption on the first S$10,000 of normal chargeable income.
50% exemption on the next S$190,000 of normal chargeable income.
The maximum income exemption is S$102,500 per Year of Assessment.
The corporate tax rate of 17% then applies to the remaining taxable amount, subject to other relevant tax provisions.
Companies should distinguish income exemptions from the corporate income tax rebate, which is a separate measure.
7. Corporate Income Tax Rebate — YA 2026
For YA 2026, IRAS announced an enhanced Corporate Income Tax Rebate of 50% of corporate tax payable.
The maximum combined benefit of the rebate and applicable Corporate Income Tax Rebate Cash Grant is S$40,000.
For YA 2026, an active company may qualify for the S$2,000 CIT Rebate Cash Grant if it made CPF contributions during calendar year 2025 for at least one Singapore citizen or permanent resident employee, excluding shareholders who are also directors of the company.
The CIT rebate is adjusted to take account of the cash grant, rather than simply adding the full cash grant to an unreduced 50% tax rebate. The total combined benefit is capped at S$40,000 per company.
IRAS generally computes the qualifying rebate in the company's tax assessment.
Important: This is a YA 2026 measure. Businesses should not automatically assume that the same rebate or cap applies to YA 2027.
8. Corporate Tax Filing for Newly Incorporated Companies
A newly incorporated Singapore company should consider its financial year end and first Year of Assessment carefully.
For example, a company incorporated in June 2026 with its first financial year ending 31 December 2026 may have corporate tax filing obligations for YA 2027.
If the company's first financial statements cover more than 12 months, special basis-period allocation requirements may apply.
The business should also assess whether it has commenced operations, earned taxable income, incurred pre-commencement expenses or qualified for an applicable tax filing waiver.
Newly incorporated companies should not assume that tax compliance starts only when IRAS issues a filing notification.
9. Does a Dormant Company Need to File a Tax Return?
Dormant status does not automatically remove every corporate tax filing obligation.
A company may qualify for an ECI waiver if it meets the applicable conditions.
For annual corporate tax returns, dormant companies may apply for a filing waiver where the relevant IRAS requirements are satisfied.
A company should distinguish between being dormant for accounting purposes and satisfying IRAS's tax filing waiver criteria.
10. What Happens If a Company Misses Its Filing Deadline?
Failing to comply with corporate tax filing obligations can result in enforcement action.
If a company fails to submit a required ECI filing, IRAS may issue an estimated Notice of Assessment based on information available to it.
Late or missing annual corporate income tax returns may also result in composition amounts, summonses or further enforcement action.
Companies should promptly determine which obligations have been missed, prepare the outstanding information and take the necessary corrective steps.
Where a company receives a Notice of Assessment, payment is generally due within one month, unless an approved arrangement applies.
11. Practical Singapore Corporate Tax Compliance Checklist
Before Financial Year End
Review the accounting records and outstanding balances.
Assess estimated profits and tax adjustments.
Confirm the company's financial year end.
Review tax residency, shareholder structure and exemption eligibility.
Within Three Months After Financial Year End
Determine whether ECI filing is required.
Prepare the estimated tax computation.
Submit ECI through myTax Portal, where applicable.
Review cash-flow requirements and payment arrangements.
Before 30 November of the Relevant YA
Finalise the financial statements.
Prepare the corporate tax computation.
Determine the applicable return type.
Review tax reliefs, credits and supporting schedules.
File Form C-S (Lite), Form C-S or Form C.
Retain the acknowledgement and supporting records.
Common Mistakes Singapore Companies Should Avoid
1. Confusing ECI with the annual corporate tax return.
These are separate filings with different deadlines.
2. Assuming nil accounting profit means no ECI filing.
The waiver requires both nil ECI and the applicable revenue condition.
3. Selecting Form C-S solely based on revenue.
Income sources and tax claims may make the company ineligible.
4. Failing to prepare a tax computation when filing Form C-S.
The supporting computation should still be prepared and retained.
5. Assuming incorporation guarantees start-up tax exemption.
Tax residency, shareholding and business-activity conditions must be considered.
6. Confusing the financial year with the Year of Assessment.
This may cause companies to identify the wrong filing deadline.
For a broader overview of ACRA annual returns, AGMs, GST, CPF and other corporate filing obligations, read our Singapore Company Compliance Calendar 2026/2027.
Frequently Asked Questions
Is ECI compulsory for every Singapore company?
No. A company may qualify for the ECI filing waiver when annual revenue does not exceed S$5 million and ECI is nil, subject to the applicable rules.
Can a company with S$150,000 annual revenue file Form C-S (Lite)?
Yes, if it also meets the other qualifying conditions for Form C-S.
Can a company with revenue above S$5 million file Form C-S?
Generally, the revenue threshold for Form C-S is S$5 million. Any applicable IRAS administrative concessions should be considered separately.
Must Form C-S companies prepare financial statements?
Yes. Although the documents generally do not need to accompany the Form C-S submission, the company must still prepare and retain the required financial statements and tax computation.
Is Singapore corporate income tax always 17% of accounting profit?
No. The prevailing rate is 17% of chargeable income after the applicable tax adjustments, while tax exemptions, rebates and credits may affect the final tax payable.
Can a foreign-owned Singapore company qualify for start-up tax exemption?
Potentially, but foreign ownership alone does not determine eligibility. The company must satisfy the relevant Singapore tax residency, shareholding and other prescribed conditions.
Is Form C-S (Lite) the same as ECI?
No. Form C-S (Lite) is an annual corporate income tax return. ECI is a separate estimated tax filing made earlier in the reporting cycle.
When is the Singapore corporate tax return due for YA 2026?
The general filing deadline for Form C-S, Form C-S (Lite) and Form C for YA 2026 is 30 November 2026.
How LGR Corporate Advisory Can Help
LGR Corporate Advisory supports companies operating in Singapore with corporate tax and regulatory compliance coordination, accounting and financial reporting, company secretarial obligations and cross-border business considerations.
For businesses operating between Singapore and Malaysia, corporate tax planning should also consider management arrangements, related-party transactions, permanent establishment exposure, withholding tax and the applicable regulatory obligations in each jurisdiction.
Need Assistance with Singapore Corporate Tax?
Whether your company is newly incorporated, preparing its first ECI filing or reviewing its annual corporate tax obligations, LGR Corporate Advisory can help you understand the requirements and organise the next compliance steps.
Speak with LGR Corporate Advisory about your Singapore corporate tax requirements.
Official References
Disclaimer: This article provides general information based on IRAS guidance reviewed as at 18 October 2026. Corporate tax obligations, reliefs and filing requirements depend on the company's circumstances and the applicable Year of Assessment. The content should not be treated as a substitute for professional advice.