#What Is EN 16931?
EN 16931 is the European standard that defines a common semantic data model for the core elements of an electronic invoice, so a single invoice structure can be recognised across EU member states. It is the foundation every European e-invoice format — XRechnung, ZUGFeRD, Factur-X, Peppol BIS — is built on.
This page explains the EN 16931 standard factually. It is not tax or legal advice — confirm your own obligations with a qualified advisor.
#What EN 16931 is
EN 16931 specifies what an electronic invoice must contain and how its data is structured — independent of any single country or software. Maintained by the European standards body CEN (technical committee CEN/TC 434), it gives every invoice element a standard identity so that a buyer's system in one country can read a supplier's invoice from another without custom mapping. It is the answer to a simple problem: before EN 16931, every country and vendor had its own invoice format.
#EN 16931 and EU Directive 2014/55/EU
The standard exists because of a law. Directive 2014/55/EU required a common European e-invoicing standard and obliged public-sector bodies across the EU to be able to receive and process invoices that conform to it. EN 16931 is the standard created to meet that requirement. The directive is the legal driver; EN 16931 is the technical specification.
#What the standard defines
- Business terms and groups: individual fields are business terms (BT-xx, e.g. the invoice number or a line net amount), organised into business groups (BG-xx, e.g. the seller's postal address). This shared vocabulary is what makes invoices interoperable.
- Two permitted syntaxes: EN 16931 invoices are expressed in either UBL (Universal Business Language) or UN/CEFACT CII (Cross Industry Invoice). Both encode the same data model.
- Business rules: validation rules (BR-xx) that a conformant invoice must satisfy — for example, that totals add up consistently.
#EN 16931 vs national formats
National formats don't replace EN 16931 — they specialise it. A CIUS (Core Invoice Usage Specification) narrows the standard for a country's needs; a profile selects a subset of it.
| Format | Country / scope | Relationship to EN 16931 | Syntax |
|---|---|---|---|
| XRechnung | Germany (B2G) | CIUS | UBL or CII |
| ZUGFeRD | Germany (B2B) | Profile (hybrid PDF) | CII |
| Factur-X | France | Profile (same as ZUGFeRD) | CII |
| Peppol BIS Billing 3.0 | Pan-EU | CIUS | UBL |
#How an invoice is validated against EN 16931
Conformance is checked by running the invoice through the EN 16931 business rules (plus any national rules), usually as machine-readable schematron tests. An invoice that breaks a rule isn't compliant.
This is exactly what Scribo automates: every invoice it generates is validated against EN 16931 by Invopop's hosted validator at generate time, before the file is returned — so non-conformant output never reaches you. Scribo produces EN 16931 formats (XRechnung, ZUGFeRD, and more) from a plain description of the invoice, free, through the web app, API, MCP server, CLI, or skill. See the compliance page for the validator and version details.
#What's changing
EN 16931 is maintained over time, and a revision is in progress that updates which syntax versions are bound to the standard. Because the underlying invoice concepts are stable, the practical impact for most senders is small — but it's why the exact version pins matter, and why Scribo states the versions it uses on its compliance page.
#Frequently asked questions
Is EN 16931 mandatory? EN 16931 itself is a standard, not a law. It became binding in practice through EU Directive 2014/55/EU, which requires public bodies across the EU to accept invoices that conform to it, and through national mandates (such as Germany's) that build on it. Whether you must send an EN 16931 invoice depends on your country and transaction type.
What is the difference between EN 16931 and Directive 2014/55/EU? Directive 2014/55/EU is the EU law that mandated a common European e-invoicing standard; EN 16931 is the standard that was created to fulfil it. The directive is the legal driver, EN 16931 is the technical specification.
Is XRechnung EN 16931 compliant? Yes. XRechnung is a CIUS (Core Invoice Usage Specification) of EN 16931 — a national interpretation that stays within the European core. ZUGFeRD, Factur-X, and Peppol BIS are likewise EN 16931-conformant.
What are BT and BG codes in EN 16931? EN 16931 defines the invoice as a set of business terms (BT-xx, individual fields like the invoice number or a line amount) grouped into business groups (BG-xx). These codes give every data element a standard identity so different systems interpret the same invoice the same way.
Does a PDF satisfy EN 16931? An ordinary PDF does not — it is unstructured. EN 16931 requires structured data in a supported syntax (UBL or CII). A hybrid format like ZUGFeRD satisfies it because it embeds that structured XML inside the PDF.
Sources: EU Directive 2014/55/EU (EUR-Lex); CEN — European Committee for Standardization; KoSIT — XRechnung.