Grand Chamber of Supreme Court reviews and summarises its conclusions on deadlines for challenging decisions of tax authorities

In its resolution in case No. 500/2276/24 dated 16 July 2025, the Grand Chamber of the Supreme Court set out important conclusions regarding the time limits for filing claims with administrative courts in tax disputes.

The key issue in this case was whether the claimant had complied with the procedural deadline for filing a claim to declare tax assessment notices (TANs) unlawful and cancel them following the completion of the administrative appeal procedure before a higher tax authority.

Conclusions of the Grand Chamber

When analysing the disputed legal relations, the Supreme Court adopted a differentiated approach to determining the time limits for filing a court claim, depending on the nature of the tax authority’s decision and whether it had been subject to prior administrative appeal. In particular:

• 6 months – applies to any decision that was not challenged through administrative appeal. The period begins on the date the claimant learned or should have learned of the violation of their rights, freedoms, or interests.
• 3 months – applies to decisions not involving the accrual of monetary obligations (e.g., regarding blocking of tax invoices), if such decisions were challenged through administrative appeal. The period begins on the date the claimant receives the decision on the outcome of the administrative appeal.
• 1 month – applies to decisions involving the accrual of monetary obligations (such as TANs), if such decisions were challenged through administrative appeal. The period begins on the day following the date the administrative appeal is completed.

Among other things, the Supreme Court resolved the debate regarding the application of the three-year (1,095-day) period provided by the Tax Code of Ukraine for court appeal. The Grand Chamber departed from its previous position, in particular that expressed in its resolution dated 19 January 2023 in case No. 140/1770/19.

According to the new position, the 1,095-day period under the Tax Code of Ukraine is merely a statute of limitation and should not be treated as the time limit for filing a claim with the court seeking to annul a TAN. Therefore, if a TAN is not challenged before a higher tax authority, the six-month period provided in the Code of Administrative Procedure of Ukraine applies.

The Supreme Court’s resolution in case No. 500/2276/24 dated 16 July 2025 is available at the link.

Additional information

This legal alert is issued to inform AVELLUM clients and other interested parties of legal developments that may affect or otherwise be of interest to them. The information above does not constitute legal or other advice and should not be regarded as a substitute for specific advice in individual cases.

For further information on appealing tax authority decisions and procedural deadlines, please contact partner Vadim Medvedev.