Validation rules

BR-12

The sum of invoice line net amounts (BT-106) is missing from the document totals.

Rule

BR-12 — official EN 16931 / XRechnung rule

Severity

error

Business term

BT-106 — Sum of line net amounts

Field in your JSON

invoice.totals.net

Detected by

tier 3 — KoSIT validator (authoritative)

Reachability

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

normbill computes every monetary total itself and always writes BT-106; supplied invoice.totals are only cross-checked, never serialized.

How to fix it

Add cbc:LineExtensionAmount to cac:LegalMonetaryTotal.

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.