EN 16931 syntax binding

Syntax binding states how each semantic term of EN 16931 is actually written in XML.

Definition

The EN 16931-1 standard defines a semantic model of the invoice: a list of business elements (amounts, parties, lines, VAT) identified by BT- (Business Term) and BG- (Business Group) codes. This model is abstract — it does not say how to write it into a file.

The syntax binding fills that gap by mapping each semantic term to a precise location in a real XML syntax.

The two bound syntaxes

Two official technical specifications provide this binding:

• CEN/TS 16931-3-2 — binding to UBL 2.1 (OASIS Universal Business Language);
• CEN/TS 16931-3-3 — binding to UN/CEFACT CII (Cross Industry Invoice, the syntax used by Factur-X and ZUGFeRD).

A further part, CEN/TS 16931-3-1, provides the common binding methodology.

Good to know

An EN 16931-compliant invoice must use one of these two syntaxes to be interoperable under Directive 2014/55/EU on e-invoicing in public procurement.

The binding makes both syntaxes semantically equivalent: the same invoice can be expressed in UBL or in CII and carry exactly the same business information.