Tax Disputes and Procedural Deadlines: New Supreme Court Practice

In tax disputes, the issue of procedural deadlines has long ceased to be merely a technical matter. In practice, the correct determination of when a limitation period begins and how long it lasts often decides the outcome of a dispute before the court even considers the substance of the tax assessment itself. Recent Supreme Court practice has only reinforced the significance of this issue. For many years, tax disputes in Ukraine were largely influenced by the concept of applying the 1095-day period established by Article 102 of the Tax Code. Part of judicial practice treated this period as the permissible timeframe for taxpayers to file claims with administrative courts. However, in its judgment of July 16, 2025, in case No. 500/2276/24, the Grand Chamber of the Supreme Court effectively changed this approach.

The Court expressly stated that the 1095-day period constitutes a statute of limitations within tax legal relations rather than a procedural deadline for filing a lawsuit. In other words, this period defines the duration of the taxpayer’s substantive right to challenge a tax authority decision, but it does not mean that a taxpayer may file a claim in court at any point within three years. Following this judgment, the system of procedural deadlines in tax disputes became significantly stricter and more formalized. If a taxpayer has not used the administrative appeal procedure, the general six-month deadline for filing a claim with an administrative court applies pursuant to Part 2 of Article 122 of the Code of Administrative Procedure.

Where a taxpayer has first pursued an administrative appeal, the situation becomes more complicated. For non-monetary disputes — for example, disputes regarding blocked VAT invoices or inclusion in the list of “risky taxpayers” — the deadline for applying to court is three months. However, for challenges to tax assessment notices and other decisions involving monetary liabilities, a special one-month deadline applies under paragraph 56.19 of Article 56 of the Tax Code.

In effect, the Supreme Court has definitively separated the general procedural provisions of the Code of Administrative Procedure from the special rules established by the Tax Code. This currently creates one of the most significant legal risks for businesses: an incorrect determination of the applicable procedural deadline may result in the loss of judicial protection regardless of the merits of the case itself.

Equally important is the issue of determining the moment from which such deadlines begin to run. This has traditionally been one of the most problematic areas in tax litigation.

The Court consistently maintains that the obligation to ensure receipt of correspondence at the registered tax address rests with the taxpayer. If an individual or company is not actually present at the registered address, fails to check the mailbox, or neglects to update registration data, such circumstances do not exempt the taxpayer from legal consequences.

In its judgment of November 13, 2025, in case No. 520/7470/25, the Court expressly confirmed that if the postal operator records the impossibility of delivering a registered letter, the date of such notation is deemed to be the date of delivery of the document to the taxpayer. Consequently, the procedural deadline begins to run even where the taxpayer has not actually become acquainted with the contents of the document.

A separate category of issues arises in connection with the taxpayer’s electronic cabinet. Ukrainian tax legislation permits official communication through the electronic cabinet system, and documents are considered duly delivered once they are uploaded to the system and an appropriate delivery receipt is generated.

In its judgment of May 9, 2024, in case No. 280/923/23, the Supreme Court emphasized that the only proper evidence of delivery is the automatically generated electronic receipt confirming delivery of the document to the taxpayer’s electronic cabinet. For businesses, this means that constant monitoring of the electronic cabinet has become essential, as ignoring electronic correspondence no longer provides any procedural protection.

Following the outbreak of the full-scale war, many taxpayers attempted to rely on martial law as grounds for restoring missed procedural deadlines. However, judicial practice in this area has also become rather strict.

In its ruling of June 22, 2022, in case No. 640/12494/20, the Supreme Court expressly stated that the mere existence of martial law does not automatically justify restoration of a missed procedural deadline. The Court requires a direct causal link between the specific wartime circumstances and the impossibility of filing a claim in due time.

For this reason, general references to wartime difficulties without proper documentary evidence usually prove ineffective. Courts assess each situation individually.