Validation rules

BR-16

The invoice has no invoice lines (BG-25) — at least one is required.

Rule

BR-16 — official EN 16931 / XRechnung rule

Severity

error

Detected by

tier 3 — KoSIT validator (authoritative)

Reachability

Only reachable when validating your own XML — normbill-generated documents cannot trigger it

invoice.lines requires at least one entry in the request schema; the UBL schema also mandates one, so the XSD tier reports line-less XML first.

How to fix it

Add at least one cac:InvoiceLine.

Official sources

• XRechnung specification (KoSIT / xeinkauf.de)
• KoSIT validator on GitHub and the XRechnung validator configuration

Every 422 from the API lists the rule id, the path in your request JSON, a plain-language message and a suggested fix — see the docs overview for the report format.