Reference
Markdown exportEN 16931
European standard defining the semantic data model for e-invoices.
Definition
European standard defining the semantic data model for e-invoices.
Why this term matters
EN 16931 supplies the semantic model used by Directive 2014/55/EU and many CIUS profiles. Under the Directive, contracting authorities and contracting entities must receive and process compliant electronic invoices for procurement contracts within its scope. National profiles, buyer rules, and delivery channels can add requirements.
Explanation
Defines which business terms (BT) and groups (BG) an EN 16931 compliant invoice can carry.
National implementations can add constraints (CIUS) and extension rules.
Common mistakes
- Confusing the semantic standard (EN 16931-1) with its syntax bindings (EN 16931-2 for UBL Invoice/CreditNote and CII).
- Sending a free-text VAT category (BT-118) instead of one of the EN 16931 UNCL5305 codes (S, Z, E, AE, K, G, O, L, M).
- Treating BT-1 (invoice number) as numeric — it is a string with sequential semantics, but the spec allows alphanumerics.
- Mismatched totals: BT-109 (Invoice total amount without VAT) must equal sum(BT-131) – sum(BT-92) + sum(BT-99) within rounding tolerance.
Frequently asked questions
Is EN 16931 the same as the EU e-invoicing standard?
Yes — Directive 2014/55/EU mandated CEN to publish a European e-invoicing standard, and EN 16931 (multi-part, published 2017, with regular amendments) is the result. Compliance with EN 16931 satisfies the directive’s semantic requirements.
Which syntaxes are EN 16931 compliant?
The EU syntax list covers OASIS UBL 2.1 Invoice and CreditNote and UN/CEFACT CII D16B. Contracting authorities and entities must receive and process them for procurement invoices within Directive 2014/55/EU’s scope. The applicable CIUS and delivery channel still matter.
How do CIUS and Extension differ from EN 16931?
A CIUS (Core Invoice Usage Specification) tightens or restricts EN 16931 (e.g., XRechnung makes BT-10 mandatory). An Extension adds new business terms (e.g., for sectors needing additional structured data). Both must remain backward-compatible with EN 16931 conformance.