Turkey's Revenue Administration has announced the publication of Tax Procedure Circular No. 134 of 3 May 2021, which provides an extension of the advance tax declaration and payment due for the first quarter of 2021 (January-February-March). Normally due 17 May 2021, the deadline has been extended to 31 May 2021. The extension also applies for taxpayers following a special (non-calendar) accounting period whose declaration date is 17 May 2021 for the relevant advance tax period.