Opt-in and buyer-driven, not universal. Exchange is decentralised via private operators (Finbite, Telema, Unifiedpost, e-arveldaja) with roaming plus Peppol. Public sector entities are registered recipients by default.
PRIMARY/SECONDARY CONFLICT — the sharpest one in this set. Sovos, Marosa, EDICOM and VATupdate all present 'Estonia mandates B2B from 2027' as near-settled. The Estonian Ministry of Finance's own guidance page, updated 12 January 2026, describes ONLY the opt-in 2025 regime and makes no mention of a 2027 mandate; no Riigikogu bill or Riigi Teataja publication could be located. DO NOT PUBLISH 2027 AS A DATE. Separately, the live buyer's right is easy to miss because it is triggered by a flag on the COUNTERPARTY's registry entry, not by your own status.
2 of 4 are primary sources. Mandate dates move — treat this page as a starting point and confirm against the primary source before committing a plan.
Work hands-on with the EN 16931 formats behind this mandate — no login, nothing uploaded.
Scrub the Estonia timeline and watch an invoice become the document each deadline will require.
Open time machine →Open a UBL, Factur-X or XRechnung file and read every EN 16931 field.
Open viewer →Generate a well-formed sample invoice to test your mapping.
Open generator →Check whether your Estonia partner is reachable on Peppol.
Open lookup →A page is a starting point. A scoped analysis gives you the specification, the mapping and the effort — in weeks, not quarters.
