Sri Lanka's Inland Revenue Department has published a Circular to Taxpayers on calculating quarterly income tax instalments, which was originally issued on 3 August 2026 and revised on 6 August 2026. The circular has been issued considering changes in the calculation of quarterly installments by the Inland Revenue (Amendment) Act No. 11 of 2026, which was certified (enacted) on 3 June 2026. As previously reported, the Act withdrew the requirement for taxpayers to submit a Statement of Estima…