EN 16931, XRechnung, ZUGFeRD: how the standards relate

The norm: EN 16931

EN 16931 is the European norm for electronic invoices. It defines which details an invoice contains (the semantic data model) and what they are called. It is the common basis on which countries build their formats.

The syntaxes: UBL and CII

The norm permits two technical notations (syntaxes) to express the data in XML: UBL and CII. You can think of them as two languages saying the same thing.

The formats in Germany

The formats build on this:

• XRechnung: the German implementation of the norm, meant for authorities, pure XML.
• ZUGFeRD: PDF/A-3 with embedded XML (CII), in several profiles.
• Factur-X: the French counterpart of ZUGFeRD, aligned in content.

The specification identifier

Every file states which specification it is built to (BT-24). Validators use it to know which rules apply. A validator shows it and checks against it.

Checking against the rules

A validator checks two levels: the schema (structure of the XML) and the business rules (for example whether the totals add up). A file can satisfy the schema and still violate rules.

• Validate e-invoice

Frequently asked questions

Do I have to know these terms?

For everyday use this is enough: XRechnung for authorities, ZUGFeRD for mixed customers. The norms matter so that validators know what they check against.

Is UBL better than CII?

No. Both are equivalent and usually irrelevant to the recipient.

What is Factur-X?

The French format with the same structure as ZUGFeRD. Both are aligned in content.

More guides

• What is an e-invoice?
• XRechnung: structure and mandatory fields
• ZUGFeRD: PDF with embedded XML
• The most important fields of an e-invoice

These guides do not replace tax or legal advice. For questions about your own case please ask your tax adviser.