EN 16931
European standard · Semantic model for electronic invoicing SIGNET support: Normative mapping — machine-verified
What it is
EN 16931 is the European standard defining the semantic model of an electronic invoice: the set of business terms an invoice must be able to express, independent of any particular file format. It is the reference model behind the EU's e-invoicing legislation, including the VAT in the Digital Age (ViDA) package, which mandates structured cross-border e-invoicing on the EN 16931 model from July 2030, preceded by cascading national B2B mandates. Common invoice syntaxes — UBL, UN/CEFACT CII, and the hybrid Factur-X format — are bindings of this one semantic model.
The standard is maintained by CEN/TC 434. Official reference →
How SIGNET supports it
EN 16931 sits in the highest of SIGNET's three support tiers: it is part of the normative mapping table in the specification. A conforming SIGNET implementation MUST be able to transform between the canonical Invoice and EN 16931-based formats without loss of the mapped fields.
The alignment is structural, not documentary. The SIGNET Invoice, InvoiceLine, and VatBreakdown objects carry EN 16931 Business Term and Business Group references field by field — 33 terms and groups in all, spanning the invoice header and totals (BT-1, BT-3, BG-4, BG-7, among others), line detail (BG-25), and VAT subtotals (BG-23). Each schema field records its BT/BG reference directly in the schema source, so traceability survives every revision of the prose specification.
This is also the one mapping in SIGNET that is not merely asserted but continuously proven. The reference repository ships a transform that projects a canonical SIGNET invoice into UBL 2.1 / Peppol BIS Billing 3.0, and an independent verifier that parses the generated output and reconciles every mapped Business Term and monetary total against the source document. Both run in continuous integration on every change to the standard, so convertibility is a tested property, not a claim.
Because the semantic alignment is at the EN 16931 layer rather than any single syntax, a SIGNET invoice is convertible to each of the standard's bindings — Peppol BIS Billing, UBL Invoice, CII, and Factur-X — and a SIGNET network can emit exactly the artefact a tax authority or Peppol Access Point expects, without bespoke integration per jurisdiction.
The reference transform is a faithful projection, not a substitute for official validation: production use should additionally apply the official EN 16931 XSD and Schematron artefacts.
Where it lives in the standard
- Standards Mapping — the normative mapping table
- EN 16931 & ViDA E-Invoicing — the runnable proof, worked numbers, and scope notes
- Schema sources:
invoice.schema.json,definitions.schema.json(InvoiceLine, VatBreakdown)