In short: EN 16931:2026 exists, but Peppol isn't using it yet

As of 15 August 2026, the answer is short: no, not yet. According to the European Commission's published overview, a new version of the European e-invoice data model, EN 16931-1:2026, was released in May 2026, and the 2017 version was formally withdrawn. But the 2017 model remains valid through the transition period. The mandatory version 3.0.21 of Peppol BIS Billing 3.0, which takes effect on 17 August 2026, still marks invoices as compliant with the 2017 standard, not the new one. For your business, that means one thing: the 17 August update didn't bring a format change. It brought fixes inside the existing 2017 model.

What exactly is EN 16931, if it's not a file format or a delivery channel?

EN 16931 defines what data an invoice actually needs to contain. It's a semantic data model, meaning it's an agreement about what an invoice is means rather than what it looks like, set by the European standardization body CEN (the Comité Européen de Normalisation). Peppol layers a delivery network, identifiers and validation rules on top of that model. UBL XML, short for Universal Business Language, an extensible markup language built for business documents, is one of several file formats that can carry this data model. A PDF invoice is not a structured e-invoice for this purpose, because a machine cannot reliably read and process its contents without a person or extra software in between.

What changes with EN 16931-1:2026, and what stays the same?

The revision is being pushed by ViDA, the EU's VAT in the Digital Age directive, whose text requires e-invoices to comply with the European e-invoice standard and its listed syntaxes (the technical formats, like UBL, in which the standard can be expressed). That specific requirement takes effect on 1 July 2030. Publishing a new version of the standard doesn't mean every business has to switch tomorrow: according to the same Commission page, member states are still drafting their migration plans, and no general deadline has been set.

How do you check whether Peppol already runs on EN 16931:2026?

Version 3.0.21 was published on 20 May 2026 and becomes mandatory on 17 August 2026, adding a new optional profile for invoice responses and refreshed code lists. But the field that actually settles the question is CustomizationID, an identifier embedded in the invoice file. The technical specifications still requires this field to start with “urn:cen.eu:en16931:2017#compliant.” Until that string changes, Peppol hasn't adopted EN 16931:2026, no matter what the release is called. Calling it the “2026 release” doesn't rewrite what the field actually says.

What this means in Estonia and Latvia

In Estonia, a company registered in the business register as an e-invoice recipient has been able to require an e-invoice from its suppliers since 1 July 2025. The Accounting Act presumes an invoice meets the legal requirements if it follows EN 16931-1, although both parties can agree on a different suitable standard instead.

In Latvia, a structured e-invoice must be in XML format and follow the PEPPOL BIS Billing 3.0 specification. Per the State Revenue Service (VID), e-invoicing has been mandatory for G2G, B2G and G2B transactions since 1 January 2025; data submission to VID starts 1 January 2026; and the B2B obligation, together with full VID reporting, kicks in from 1 January 2028.

A 30-minute checklist for your invoicing software

Before you touch any export settings or integrations, ask your software provider directly:

  • Which version of Peppol BIS Billing 3.0 and which CustomizationID value are we sending today?
  • Does the 17 August 2026 update apply automatically, or does it need action on our end?
  • Do outgoing UBL invoices and credit notes get validated before they're sent?
  • What's the provider's roadmap for the eventual move to EN 16931:2026?

Any Peppol invoice heading to Latvia currently has to clear validation built around the 2017 model, because CustomizationID still points to that version. That won't change on 17 August, even though the content inside the invoice, things like the VAT breakdown and reference numbers, is checked against the updated rules.

FAQ

Does Peppol already use the EN 16931:2026 standard?

No, as of August 15, 2026, it is not used. Peppoli version 3.0.21, which will become mandatory on August 17, 2026, will still identify invoices according to the 2017 standard. This is indicated by the CustomizationID field in the invoice, which requires the identifier "urn:cen.eu:en16931:2017#compliant".

What is the difference between EN 16931 and Peppol?

EN 16931 is a European standard that describes what data should essentially be on an invoice – it is a semantic data model. Peppol adds to it a transmission network, identifiers and validation rules. UBL XML is one of the possible file formats in which this data model is expressed.

What does EN 16931:2026 mean for Estonian and Latvian companies?

In Estonia, a company can request an e-invoice from a supplier from 1 July 2025, which must comply with the EN 16931-1 standard. In Latvia, a structured e-invoice must be in XML format and comply with the PEPPOL BIS Billing 3.0 specification. In both cases, the 2017 model is currently valid.

When will EN 16931:2026 become mandatory?

According to the European Commission, migration plans are still being developed in the Member States and no general deadline has been set. The ViDA Directive requires e-invoices to comply with the European e-invoice standard from 1 July 2030.