Tax deadlines in Sri Lanka are split into two key categories: payment deadlines and return filing deadlines. Knowing which applies to you and when is essential to avoid penalties and interest charges. Between September and December 2025, several major Inland Revenue Department (IRD) deadlines fall due, affecting both individuals and businesses. This blog breaks them down clearly, with tables for easy reference, and explains when the monthly vs annual filing applies.
1. Payment Deadlines
Payment deadlines are when you must pay tax to IRD, either as instalments, deductions, or final settlements.
| Date | Type of Payment | Applies To |
| 30 Sept 2025 | Final Payment of Income Tax (Y/A 2024/2025) | Individuals, partnerships, companies |
| 30 Sept 2025 | VAT on Financial Services – Final Payment (Assessment Year Basis) | Financial institutions |
| 15 Oct 2025 | APIT Payment (September payroll) | Employers on behalf of employees |
| 15 Oct 2025 | AIT/WHT Payment (interest, fees, others) | Banks, companies, and entities making payments |
| 15 Oct 2025 | 2nd Income Tax Instalment (Y/A 2025/2026) | Individuals, partnerships, companies |
| 15 Nov 2025 | APIT Payment (October payroll) | Employers |
| 15 Nov 2025 | AIT/WHT Payment (October deductions) | Banks, companies, and payers |
| 15 Dec 2025 | APIT Payment (November payroll) | Employers |
| 15 Dec 2025 | AIT/WHT Payment (November deductions) | Banks, companies, and payers |
2. Return Filing Deadlines
Return filing deadlines are when you must submit forms or statements to IRD, showing income, VAT, or tax deductions.
| Date | Return Due | Applies To |
| 30 Sept 2025 | VAT on Financial Services Return (Assessment Year Basis) | Financial institutions |
| 31 Oct 2025 | VAT Return (Quarterly: July–Sept 2025) | VAT-registered businesses |
| 30 Nov 2025 | Return on Income (Y/A 2024/2025) | Individuals, partnerships, companies |
| 31 Dec 2025 | VAT Return (Monthly: November 2025) | VAT-registered businesses |
Monthly vs Annual Obligations
- Monthly obligations apply mainly to employers and businesses with ongoing deductions:
- APIT (Advance Personal Income Tax) must be deducted from salaries every month and remitted by the 15th of the following month.
- AIT/WHT on interest, fees, and certain payments also fall due monthly on the 15th.
- VAT Returns are monthly for businesses above the registration threshold.
- Quarterly/Annual obligations:
- Some businesses file VAT quarterly if they qualify under IRD rules.
- Income Tax Instalments (SET) are paid quarterly; however, the Return of Income itself is filed annually.
- Final Income Tax Payments for an assessment year are annual obligations.
In short, Employers and VAT-registered businesses must keep track of monthly deductions and filings, while annual taxpayers focus on quarterly instalments and the final return.
Calculate your Tax with the TaxPro Tax Calculator
Why These Deadlines Matter
Meeting these deadlines is about protecting your finances. Late submissions or payments can trigger interest charges, penalties, and additional compliance risks. For businesses, repeated delays can also damage credibility with both regulators and stakeholders. Staying ahead of these dates ensures you remain compliant and stress-free.
For a complete overview of all due dates, refer to the official IRD Tax Calendar 2025 (PDF).
How TaxPro.lk Can Help
At TaxPro.lk, we simplify compliance by:
- Tracking both payment and return filing deadlines.
- Managing monthly, quarterly, and annual submissions.
- Ensuring no penalties with timely reminders and expert filing support.
Don’t leave compliance to chance. Partner with TaxPro.lk and stay ahead of every deadline.