2026 Tax Filing Deadlines Every Sri Lankan Business Must Know

Sri Lankan businesses must adhere to a strict tax calendar dictated by the Inland Revenue Department (IRD). The corporate tax year runs from April 1 to March 31. Key deadlines include quarterly income tax payments due by the 15th of May, August, November, and February, and the annual income tax return deadline on November 30.Annual Income Tax & Audit DeadlinesNovember 30, 2026: Final deadline to file the Corporate Income Tax Return for the preceding Year of Assessment (Y/A 2025/2026). E-filing is strictly mandatory.November 30, 2026: Final deadline to settle the Balance of Income Tax Payment (if any) for Y/A 2025/2026.Quarterly Advance & Installment DeadlinesIncome tax is paid in advance on a quarterly basis. Under recent amendments (including the Inland Revenue Amendment Act No. 11 of 2026), these installments are primarily computed based on the previous year's tax liability:1st Quarter: Due on or before May 15, 20262nd Quarter: Due on or before August 15, 20263rd Quarter: Due on or before November 15, 20264th Quarter: Due on or before February 15, 2027Monthly & Periodic Compliance15th of Every Month: Deadline to remit Advance Personal Income Tax (APIT), Withholding Tax (WHT), and Advance Income Tax (AIT) deductions made in the

previous month.20th of Every Month: Deadline to file and remit Social Security Contribution Levy


(SSCL) returns and payments for the preceding month.Last Day of Every Month: Deadline to file the Monthly VAT Return and remit VAT collected in the preceding month.Annual StatementsApril 30, 2026: Deadline to submit the APIT Annual Statement for the preceding Year of Assessment.Note: As IRD due dates often fall on public or bank holidays, it is advised to process your e-payments and return filings slightly ahead of the official due dates. For detailed circulars and guides, verify your specific business obligations on the Inland Revenue Department Sri Lanka Portal.