Late Payment Interest Calculator

Late payment interest is the interest applied to the tax principal from the normal due date to the assessment date for additionally, ex officio, or administratively assessed taxes. It is calculated according to Law No. 6183.

The late payment interest rate is the same as the late surcharge rate, which is 2.5% per month in 2025. This rate can be changed by a Council of Ministers decision.

Late payment interest is applied to taxes assessed additionally or ex officio as a result of a tax audit. Late surcharges are applied to taxes that are assessed through normal declarations but not paid by the due date.