Slovenia Pushes Back Mandatory B2B E-Invoicing to 2028

Slovenia has again postponed the introduction of mandatory electronic invoicing for business-to-business (B2B) transactions, shifting the start date to 1 January 2028. The requirement was initially scheduled for 1 June 2026, before a draft law in early 2025 proposed a deferral to 1 January 2027. Following further consultation and legislative review, the final law adopted in October 2025 introduced another delay, giving businesses additional time to adapt their invoicing systems and processes.

Alongside the revised timeline, Slovenia also updated its national e-invoicing framework. The country’s long-standing e-SLOG model was modified in October to incorporate compatibility with the Peppol network, aligning Slovenia more closely with broader European e-document exchange standards. Another significant policy shift was the removal of the proposed real-time reporting obligation to the Financial Administration (FURS), reducing the administrative burden that businesses would have faced under the earlier draft.

The legislation also confirms that B2C invoices may continue to be issued in paper format, limiting the mandate strictly to B2B transactions conducted domestically.

Under the updated framework, taxpayers will be able to exchange e-invoices through four channels: their own API-based direct exchange systems; service providers registered with the EPOS e-route; the international Peppol network; or the free mini Blagajna application intended for small-scale operators.

Slovenia will allow multiple e-invoicing standards, including the national e-SLOG scheme, the EU EN 16931 standard, and any internationally recognised structured format mutually agreed by the trading parties.

A tiered penalty regime will accompany the mandate when it goes live in 2028. Corporate entities may face fines of up to €3,000, while sole traders could be fined as much as €1,500. Designated responsible officers within organisations face smaller penalties ranging from around €100 to €500.

Slovenia has been a regional leader in digital invoicing, having introduced mandatory B2G e-invoicing in 2015—well ahead of the EU-wide obligation in 2019. The updated roadmap underscores the country’s intention to modernise its invoicing ecosystem while giving businesses sufficient time to prepare.