EN 16931 — the European e-invoicing norm

EN 16931 is the European standard defining the semantic data model of an electronic invoice — the fields, their meaning and business rules. National formats (XRechnung, NLCIUS, Peppol BIS) are CIUS profiles — compliant restrictions of this core model.

What the norm defines

The core invoice model: ~160 business terms (seller, buyer, lines, VAT breakdown, payment means, references) with cardinalities and rules.
Two syntaxes: UBL 2.1 and UN/CEFACT CII — an EN 16931 invoice is expressed in one of them.
Compliance mechanism: CIUS (restrictions) and extensions (additions, used sparingly, e.g. for construction industry needs).

Why it matters

The EU e-invoicing directive (2014/55/EU) obliges every European public buyer to accept EN 16931 invoices, and the B2B mandates arriving across Europe (Belgium, Germany, France, Poland, Slovakia…) all define their required formats as EN 16931-compliant. Learn how the network’s own profile relates in Peppol BIS Billing 3.0, or test a file in the validator.

Updated: August 29, 2026

Frequently asked questions

Is EN 16931 a file format?

No — it is a semantic model. It defines what an invoice must express; two syntaxes (UBL and CII) are standardized bindings of that model to XML.

What is a CIUS?

A Core Invoice Usage Specification — a restriction of EN 16931 that stays fully compliant (it may forbid or tighten, never contradict). XRechnung, NLCIUS and Peppol BIS Billing 3.0 are CIUS profiles.