Since its entry into force in 2011, the Tax Code has contained a rule that stipulates that if the taxpayer does not request a refund of the refundable overpayment within 6 years from the end of the year in which the overpayment occurred, this overpayment expires and becomes public budget income.

However, in its judgment of 8 January 2026, No. 9 Afs 18/2025-44, the Supreme Administrative Court (“SAC“) concluded that the six-year lapse period within which it is possible to request the usage or refund of a refundable overpayment runs separately for each partial refundable overpayment. Thus, the personal tax account does not record only one overpayment as the sum of all prescriptions and payments, but a number of overpayments, each in a specific amount, with a specific date of its occurrence, and thus a specific date until which it is necessary to apply for its refund.

This period is not interrupted by the occurrence of other refundable overpayments (for which a separate six-year period begins to run) or the occurrence of a tax liability, provided that this tax liability is also paid by the taxpayer within its due date. In such a case, it is this specific payment of the taxpayer that is used to pay the tax liability, not the already existing overpayment.

In addition, in the opinion of the SAC, the tax administrator is not obliged to notify the taxpayer of the existence of a refundable overpayment, or even of the approaching end of the deadline for requesting its refund. According to the SAC, it is entirely up to the taxpayer to take an active interest in the status of personal tax accounts, including the possible existence of refundable overpayments. The issue of identifying existing overpayments on a personal tax account, or in a statement in which all overpayments are to be recorded, is not a simple matter at all.

At the same time, the SAC’s judgment may have an impact on the choice of the procedural strategy of taxpayers from the point of view of tax payment, because in the light of the SAC’s conclusions, in some cases it may become problematic to maintain an overpayment in order to eliminate the occurrence of late payment interest in the event of a possible additional tax assessment.

At Deloitte, we have extensive experience in this area and we are ready to help you not only with the identification of any overpayments recorded on your personal tax accounts, their disposal, but also with the selection of the optimal procedural strategy. Thus, if you are not sure whether there is an overpayment on your personal tax account and how to prevent its irreversible expiration, contact us.