Sole proprietors paying salaries to employees must file an Employer's Return.
The Employer's Return is the form, employers use to report employee income.

You may apply for an extension to obtain additional time, though such requests are granted on a limited basis. Late filings may also result in penalty charges.

If any changes occur after submission, you can file an amended return to reflect the updated information.

Tax filings are administered by the Inland Revenue Authority of Singapore (IRAS). For Corporate Income Tax, companies can file their Estimated Chargeable Income (ECI) within three months of their financial year-end, followed by the Final Tax Return (Form C-S/C) by November 30th. Regarding Personal Income Tax, individuals report their total annual income every April. Tax payments are generally due within one month from the issuance of the Notice of Assessment (NOA).

IRAS enforces strict deadlines. If you are unable to file by the due date, it is imperative to file the return immediately or submit a formal request for an extension. Non-compliance may result in late filing penalties or additional surcharges. However, if there are justifiable grounds for the delay, you may submit an appeal for a penalty waiver.

If changes are required after the submission, you can reflect the updated information by filing an amended or a revised tax return.