📈 Key Sri Lanka Income Tax Deadlines Before Year-End 2026

Sri Lankan taxpayers face crucial income tax compliance milestones between October and December 2026. Following the Inland Revenue (Amendment) Act, No. 11 of 2026, structural updates affect withholding taxes, quarterly instalments, and penalty waivers. • Key Deadlines & Requirements: • 15th Monthly (Oct/Nov/Dec): Monthly remittance deadline for Advance Income Tax (AIT) and Advance Personal Income Tax (APIT). 5% Withholding Tax (WHT) applies to service fees exceeding Rs. 100,000/month for expanded service/professional categories (e.g., IT specialists, advisers, auditors, coaches). • 15 November 2026: 2nd quarterly instalment for Y/A 2026/27 due. The Statement of Estimated Tax (SET) is abolished; payments now use the formula $(A - C) \div B$ based on 2025/26 taxable income. (Pay by 13 Nov if paying offline). • 30 November 2026: Return of Income for Y/A 2025/26 filing deadline. Requires audited accounts, tax computations, WHT schedules, and Transfer Pricing forms. Filing deadline also applies to Y/A 2026/27 instalment attachments. • 2 December 2026: Full relief on late payment interest for tax assessments up to Y/A 2024/25, provided full principal tax is settled. • 31 December 2026: Deadline for Country-by-Country (CbC) reporting notifications and reports for qualifying MNE groups. • Compliance Risk: • Failure to pay triggers a 1.5%/month interest rate plus up to 20% penalty on unpaid balances (10% on quarterly shortfalls). WHT non-compliance carries penalties up to Rs. 200,000 per Y/A.