Validation rules

BR-Z-10

A zero-rated (Z) VAT breakdown must not carry a VAT exemption reason (BT-120) or reason code (BT-121).

Rule: BR-Z-10 — official EN 16931 / XRechnung rule
Severity: error
Business term: BT-120 — VAT exemption reason
Field in your JSON: invoice.tax_exemptions[*].reason
Detected by: tier 3 — KoSIT validator (authoritative)
Reachability: Only reachable when validating your own XML — normbill-generated documents cannot trigger it

invoice.tax_exemptions only accepts categories E, AE, K, G and O, and the serializer writes reasons only into those breakdowns.

How to fix it

Remove TaxExemptionReason/TaxExemptionReasonCode from the zero-rated TaxSubtotal in your XML.

BR-Z-10 auf Deutsch — was bedeutet der Fehler?

Eine Nullsatz-Aufschlüsselung (Kategorie Z) darf keinen Befreiungsgrund (BT-120) oder Befreiungscode (BT-121) tragen. invoice.tax_exemptions akzeptiert nur E, AE, K, G und O; die Meldung betrifft extern erzeugtes XML.

So beheben Sie den Fehler

Entfernen Sie TaxExemptionReason/TaxExemptionReasonCode aus dem Nullsatz-TaxSubtotal in Ihrem XML.

Official sources

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.

Or try it live: drop any XRechnung XML on the free validator — same KoSIT-backed report, no account.