YA 2026 Corporate Tax Filing Checklist: Form C-S, C-S Lite or Form C?
Companies that are required to file must submit their YA 2026 Corporate Income Tax Return by 30 November 2026. This includes many companies that made a loss, carried out little activity or believe no tax is payable.
The filing deadline is only one part of the process. A company must select the correct return, complete its accounting records, prepare the necessary tax adjustments and ensure the authorised person can access the IRAS filing service through Corppass.
Starting early allows time to correct bookkeeping gaps, obtain documents and resolve tax questions before the deadline.
What Does YA 2026 Cover?
The Year of Assessment is the year in which income earned during the relevant basis period is assessed. For a company with a 31 December financial year-end, YA 2026 generally relates to the financial year ended 31 December 2025.
Companies with a different financial year-end will have a different basis period. Confirm the company's accounting period before preparing the return rather than assuming every YA 2026 filing covers the 2025 calendar year.
YA 2026 Filing Deadline
The deadline is 30 November 2026. Filing is completed online through myTax Portal.
The annual Corporate Income Tax Return is separate from Estimated Chargeable Income, which may have an earlier deadline based on the company’s financial year-end. JWC’s Estimated Chargeable Income (ECI) guide explains the requirement, waiver conditions and filing process.
Company directors remain responsible for timely and accurate filing even when a tax agent or external accountant has been appointed. According to IRAS’s guidance on late filing or non-filing of Corporate Income Tax Returns, a company may receive an estimated Notice of Assessment, be offered a composition amount of up to S$5,000 per offence or face further enforcement action.
Which Corporate Tax Form Should Your Company File?
IRAS sets different eligibility and submission requirements for Form C-S, Form C-S (Lite) and Form C. The correct return depends on factors including the company’s annual revenue, income profile and tax claims.
Form C-S (Lite)
Form C-S (Lite) is for a company that qualifies for Form C-S and has annual revenue of S$200,000 or below. It requires only six essential fields, making it the simplest corporate income tax return.
The company must still prepare accurate accounts and a tax computation. A shorter return is not a lower record-keeping standard.
Form C-S
A company can generally use Form C-S if it:
Form C-S filers are not required to submit financial statements and tax computations with the return, but they must prepare and retain them. IRAS may request the documents later.
Form C
Form C applies when the company does not qualify for Form C-S, Form C-S (Lite) or the Form for Dormant Company.
Financial statements, tax computations and supporting schedules must be filed together with Form C. This form is commonly required for larger or more complex companies and for companies making claims that are excluded from the simplified returns.
Form for Dormant Company
An active-status company that did not carry on business and had no income during the financial year may use the Form for Dormant Company, subject to the applicable conditions.
If myTax Portal shows the company as "No Business Done" because IRAS has granted a filing waiver, no return is required for that period. If the company has restarted business, it should update its status and request the relevant return instead of relying on an old waiver.
Do Loss-Making Companies Need to File?
Yes, if the company carried on business or received income during the year. A loss does not automatically remove the filing obligation.
Filing the return also ensures that eligible unutilised losses, capital allowances or donations are reported correctly for potential use under the applicable tax rules. Poor or late reporting can make future tax positions harder to support.
What About Newly Incorporated Companies?
A company incorporated in 2025 generally needs to file YA 2026 if it closed its first set of financial statements in 2025 and derived income or started business during 2025.
If it did not commence business or receive income, or did not close its first set of accounts in 2025, a YA 2026 return may not be required. New companies should confirm their first financial year-end and filing notice through myTax Portal.
Documents to Prepare Before Filing
Use this checklist as a starting point:
Accounting records
Tax information
Filing access
A Practical Filing Workflow
1. Close the accounts
Complete bank reconciliations, post year-end adjustments and investigate unusual balances. Tax work should not begin from incomplete management accounts. Companies that need help completing their year-end accounts and maintaining reliable financial records can explore JWC’s accounting and bookkeeping services.
2. Review taxable and non-taxable income
Identify trade income, investment income and other revenue. Check whether foreign-sourced amounts were received in Singapore and whether exemptions or special treatment may apply.
3. Review deductible and non-deductible expenses
An expense recorded in the accounts is not automatically deductible for tax. It must generally be wholly and exclusively incurred in producing income and must not be capital or specifically prohibited in nature.
4. Prepare capital allowance claims
Accounting depreciation is normally added back in the tax computation. Qualifying capital expenditure may instead receive capital allowances under the tax rules.
5. Check available exemptions, reliefs and rebates
Review eligibility for the start-up tax exemption or partial tax exemption and confirm how the enhanced YA 2026 Corporate Tax rebate affects the company’s final tax position.
6. Select the correct form
Use the final revenue, income profile and tax claims to determine whether Form C-S (Lite), Form C-S or Form C applies.
7. Review and submit
Reconcile the return to the tax computation, financial statements and prior-year balances. Submit before 30 November and retain the acknowledgement.
8. Review the Notice of Assessment
Compare IRAS's assessment with the filed return. A revision or objection generally must be submitted within two months from the date of the Notice of Assessment.
Common YA 2026 Filing Mistakes
Examples can include expenses related to S-plated cars or interest on assets that do not produce income. Review expense categories instead of copying the accounting profit directly into the return.
Missing sales, cash transactions, invoices or receipts can distort the return. Reconcile revenue to bank receipts, invoicing records and GST information where applicable.
For Form C-S (Lite), the adjusted profit or loss before capital allowances is the accounting result after tax adjustments. It is not simply the total amount of adjustments.
If the company has adopted a non-Singapore Dollar functional currency, ensure its corporate profile has been updated appropriately.
Directors should review the final filing, understand the main tax positions and ensure the return is submitted on time.
Frequently Asked Questions
Does a company need audited financial statements to file tax?
Not every company requires an audit. However, every company must maintain proper accounting records and prepare financial information sufficient to support its return. Audit exemption and tax filing are separate matters.
Can the company file before its accounts are final?
The return should be based on complete and supportable financial information. Filing from provisional records increases the risk of errors and later revisions.
What happens after filing?
IRAS reviews the return and issues a Notice of Assessment. The company should check the assessment and arrange payment by the stated due date.
Prepare Before November
Corporate tax filing is easier when bookkeeping, supporting documents and tax schedules are kept current throughout the year. Waiting until November can turn a manageable review into a rushed reconstruction exercise.
For a shorter deadline-focused reminder, read JWC’s Act Now: Corporate Tax Filing Due 30 November.
JWC Accounts & HR can help your company finalise its accounts, prepare the tax computation, select the correct return and complete the YA 2026 filing accurately and on time. Explore our corporate tax filing services to learn how our team can support your company throughout the filing process.