The Statutory Submission Cycle
The Singapore tax year runs from 1 January to 31 December. For individual taxpayers, the filing window opens on 1 March and closes strictly on 15 April for paper submissions, or 18 April for e-filing. Failure to comply with these windows results in immediate late filing penalties and potential summons.
The Inland Revenue Authority of Singapore (IRAS) operates on a "Pre-filling" system for employees whose companies participate in the Auto-Inclusion Scheme (AIS). This means your employment income is automatically uploaded to the portal. However, taxpayers remain legally responsible for verifying the accuracy of these figures and declaring additional income such as rental yields or trade profits.
Understanding the distinction between tax residency and physical presence is critical. You are generally considered a tax resident if you stayed or worked in Singapore for 183 days or more in the previous calendar year. Residents benefit from progressive tax rates and can claim various IRAS personal tax reliefs to lower their chargeable income.