Slovenia confirms B2B e-invoicing dates: provider registration from 1 April 2027, mandate from 1 January 2028

What changed in detail

Slovenia’s Zakon o izmenjavi elektronskih racunov in drugih elektronskih dokumentov (ZIERDED) was adopted by the Drzavni zbor on 23 October 2025 and published in Uradni list RS No. 85/2025 of 6 November 2025, at item 3032. It requires business entities to exchange exclusively structured electronic invoices — through registered exchange-route providers or Peppol — for mutual supplies of goods and services performed in Slovenia. Under Article 28, the law entered into force on the thirtieth day after publication, but its provisions begin to apply from 1 January 2028, except the provisions of Chapter 4 on the registration and listing of exchange-route providers, which apply from 1 April 2027. The law transposes Council Directive (EU) 2025/516.

What it means

The law itself is not new — it passed in October/November 2025. What changed this week is that its dates are now confirmed rather than provisional, and the date that actually matters first is not the headline 2028 figure. Chapter 4’s provider-registration regime opens on 1 April 2027, nine months ahead of the B2B obligation itself, because exchange-route providers and Peppol access points have to exist and be listed before any business can route an invoice through one. A business that reads only “1 January 2028” and waits accordingly will find, in early 2027, that the providers it needs to choose from are only just being registered — the real planning clock starts in April 2027, not January 2028.