From 26 February 2026, the procedure for sending tax notices of assessment changes: what it means for business

From the end of February 2026, the updated procedure for sending tax notices-decisions (TNDs) comes into force, adopted to implement amendments to the Tax Code of Ukraine and subordinate acts of the Ministry of Finance; its purpose is to digitalize communication between the State Tax Service and taxpayers, strengthen the evidentiary force of electronic documents, and reduce disputes regarding the service of TNDs. Tax authorities previously considered a TND to be served from the moment of dispatch, whereas taxpayers — only from the moment of actual receipt, and courts mostly supported the latter approach, so the legislator clarified the procedure for sending tax decisions in order to remove these conflicts.​

Main innovations of the mechanism
The new regulation defines three equivalent channels for sending TNDs:
· through the taxpayer’s electronic cabinet – the main and priority method. The document is considered served from the moment it is delivered to the cabinet and the system confirms delivery;​
· by postal service – by registered mail with delivery confirmation;​
· personal delivery to an official or authorized representative against signature.​

The key innovation is the strengthening of the role of the electronic cabinet. If previously electronic delivery was viewed as an additional option, it now becomes the basic model of communication. Accordingly, the absence of any fact of viewing the document does not release the taxpayer from the presumption that it has been received. This approach is similar to electronic litigation and electronic notification systems in the area of public procurement.​

It is separately specified that if a TND is sent simultaneously by several methods (for example, through the electronic cabinet and by post), the legally significant moment is the first event of service, that is, the date when the taxpayer had the opportunity to familiarize themself with the document.​

Safeguards for taxpayers and appeal deadlines
The reform changes the way deadlines are calculated: the 10‑day period for administrative appeal and the 30‑day period for filing a claim now run from the date of service of the TND by any lawful method, so an electronic notice is treated the same as a paper one. To avoid legal uncertainty, the taxpayer should regularly check the electronic cabinet and, in case of technical failures, record the impossibility of access (for example, by contacting the STS support service).​

Liability for electronic negligence
The new procedure brings tax communication closer to the standards of digital trust, but at the same time introduces the taxpayer’s “digital responsibility”: ignoring notifications or failing to monitor the cabinet may lead to the tax obligation being deemed agreed. If the taxpayer does not have a proper electronic signature or has not ensured the technical conditions for receiving electronic TNDs, the risk of non‑receipt of notifications and the consequences of such negligence are borne by the taxpayer.​

Administrative and judicial perspective
The updated procedure is expected to reduce the number of court disputes over “proper service”. Administrative courts have traditionally taken the side of the taxpayer if the STS could not prove actual receipt of decisions. Now that the law clearly states that confirmation of delivery of an electronic document is proof of service, there will be less room for manipulation.​

However, in practice disputes may still arise regarding proper authentication of the taxpayer in the system, the exact moment of generation of delivery receipts, and the existence of technical errors in the STS system. Case law will likely develop guidelines for interpreting these issues during 2026–2027.​

Practical tips for businesses and advisers
Given the digital transition, business entities are advised to:

1. Check the validity of email addresses and electronic signatures of managers.​
2. Ensure regular monitoring of notifications in the STS electronic cabinet.​
3. Set up an internal procedure for responding to TNDs – designate a person responsible for promptly informing the accounting or legal department.​
4. Keep system delivery receipts and technical messages about failures.​
5. In case of doubt, appeal decisions without waiting for formal reminders.​

Timely reaction helps avoid a tax decision being deemed agreed “by default” and preserves the right to legal protection.​

Electronic innovations as part of a broader digital strategy
The updated procedure for sending TNDs is part of the state’s overall digital policy aimed at fully abandoning paper document flow in tax relations by 2028. It is aligned with European regulations on electronic identification (eIDAS) and the assurance of electronic transactions.​

In effect, Ukraine is introducing its own model of “tax digitalization”, in which every tax action is confirmed by an electronic trail. This strengthens trust between the state and business, since any dispute can be checked using system technical logs rather than paper correspondence.​

Conclusions
From 26 February 2026, electronic communication between the taxpayer and the tax authority will become mandatory and legally self‑sufficient, which will increase the transparency and speed of tax procedures but will require more attention from businesses. If you face questions or problems related to the application of the updated procedure for sending TNDs, its legal consequences, or the appeal process, you should consult a tax lawyer or an administrative law specialist to assess your situation and develop a protection strategy.

Author: Ihor Yasko, Managing Partner at “WINNER” Law Firm, PhD in Law.