🎧 Listen to This Article
The Hungarian Tax and Customs Authority (NAV) has announced significant updates to the Online Számla (Online Invoice) system’s business validation rules, following a two-month public consultation phase. The revised validation framework, which incorporates taxpayer feedback submitted via GitHub, will take effect on September 15, 2025.
Objective: Higher Data Accuracy and Quality
The updated validation logic is part of NAV’s ongoing efforts to enhance the accuracy of invoice reporting and improve data quality—a priority that serves both tax authority operations and taxpayer services, such as the eVAT (eÁFA) system.
Key Changes in Validation Rules
NAV reviewed stakeholder input and has modified several elements of the initial validation draft. The changes include:
- 3 new WARN messages added
- 3 existing WARN messages deactivated
- 1 INFO message upgraded to WARN
- 15 WARN messages reclassified as ERROR (reduced from the originally planned 21)
This distinction between WARN and ERROR is crucial:
- ERROR messages indicate technical or substantive issues that block data submission.
- WARN messages do not block submission, but highlight business logic errors that may result in incorrect invoice reporting and often require review or correction.
Practical Implications for Taxpayers and Developers
To prevent data errors and ensure consistent quality, NAV strongly recommends that businesses and developers periodically review validation messages returned by the Online Invoice system and take corrective action where necessary.
This is particularly important for those using machine-to-machine (M2M) interfaces or web-based API queries within the Online Invoice and eVAT systems—both of which are seeing increased adoption.
Testing & Go-Live Timeline
- Testing environment: New rules active from September 1, 2025
- Live (production) environment: Enforcement begins September 15, 2025
For further details, clarification, contributions, or any concerns regarding this article, please get in touch with us at editorial@tax.news. We value your feedback and are committed to providing accurate and timely information. Please note that our privacy policy will handle all inquiries.
