Definition
Finance and Economy Inland Revenue Authority of Singapore
The period of income and expenses used to determine taxable income for a particular Year of Assessment.
Example: The basis period for YA 2026 is the company's financial year ending in 2025.
Also known as: tax basis period
Context: For a company, the basis period is generally the financial year preceding the Year of Assessment and usually does not exceed 12 months.
Source checked for Basis period (opens in a new tab) Checked 2026-08-11