Sri Lanka Provisional Tax Ait

---
name: sri-lanka-provisional-tax-ait
description: "Sri Lanka provisional tax via Advance Income Tax (AIT) quarterly instalments under s 90 of the Inland Revenue Act — who pays, calculation, due dates and penalties."
license: "AGPL-3.0-or-later (code) / OpenAccountants Guide License v1.0 (content)"
metadata:
  source: openaccountants
  openaccountants_url: "https://www.openaccountants.com/skills/sri-lanka-provisional-tax-ait"
  jurisdiction: "LK"
  tax_year: "2025"
  last_updated: "2026-07-13"
  reviewed_by: "Lal kumarasiri"
---

# Sri Lanka Provisional Tax / Advance Income Tax (AIT)

## Sri Lanka Provisional Tax / Advance Income Tax (AIT)

- **Companies (all CIT payers)** — All resident companies with a CIT liability are required to pay quarterly AIT instalments under s 90 of the IRA. Also applies to non-resident companies with a Sri Lanka tax liability.  _(IRA s 90)_
- **Individuals with business income** — Self-employed individuals and individuals with business income (not fully covered by APIT withholding) must make quarterly instalment payments.  _(IRA s 90; IRD AIT Individual Guidance)_
- **Basis of calculation** — Instalments are calculated based on: (a) the prior year's assessed tax liability (most common method), OR (b) an estimate of the current year's income tax liability. Companies may choose whichever is appropriate.  _(IRA s 90)_
- **Exclusions from AIT base** — Gains from realisation of investment assets (capital gains) are excluded from the AIT instalment calculation base.  _(IRA s 90)_
- **Q1 instalment** — Due by 15 July (for Y/A 1 April–31 March)  _(IRA s 90; IRD AIT Payment Schedule)_
- **Q2 instalment** — Due by 15 October  _(IRA s 90; IRD AIT Payment Schedule)_
- **Q3 instalment** — Due by 15 January  _(IRA s 90; IRD AIT Payment Schedule)_
- **Q4 instalment (balance)** — Due by 15 April (after year-end). Final balance of tax (after deducting all AIT instalments and WHT credits) due with the annual return by 30 November.  _(IRA s 90; IRD AIT Payment Schedule)_
- **Penalty for underpaid instalments** — 10% penalty on the underpaid or unpaid AIT instalment amount. percent  _(IRA s 90; IRD AIT Penalty Notice)_
- **Credit against final tax** — AIT instalments paid are credited against the final CIT liability assessed at year-end. Excess AIT (overpayment) may be refunded or carried forward.  _(IRA s 90; IRD Return Processing Guidance)_
- **WHT credit** — Withholding taxes deducted from income received (e.g. AIT on dividends, interest) are also credited against the final CIT/personal income tax liability.  _(IRA s 90B; First Schedule; IRD AIT/WHT Credit Guidance)_
- **Payment method** — Via RAMIS (IRD online portal) or through authorised banking channels.  _(IRD RAMIS – www.ird.gov.lk)_

## Today's figures and who stands behind this skill

This file is an AI skill (tax rules your AI follows) from OpenAccountants, copied on 2026-07-13. Rates, thresholds and deadlines change. For the current version of this skill, its official sources and the named accountant (if any) who stands behind it, call `get_skill` with slug `sri-lanka-provisional-tax-ait` on the OpenAccountants connector (https://www.openaccountants.com/connect), or read https://www.openaccountants.com/skills/sri-lanka-provisional-tax-ait. If neither is available, confirm every figure against the official source pages cited above before relying on it.