Validation rules

BR-O-09 — EN 16931 rule

The tax amount (BT-117) of the "not subject to VAT" (O) breakdown must be 0.

Rule: BR-O-09 — official EN 16931 / XRechnung rule
Severity: error
Business term: BT-117 — VAT category tax amount
Field in your JSON: invoice.lines
Detected by: tier 3 — KoSIT validator (authoritative)
Reachability: Triggerable from your request JSON (generate & validate)

How to fix it

Omit line.vat on O lines (and vat on O allowances/charges) — a non-zero rate still flows into the VAT computation even though no rate is printed for category O.

BR-O-09 auf Deutsch — was bedeutet der Fehler?

Der Steuerbetrag (BT-117) der O-Aufschlüsselung (nicht umsatzsteuerbar) muss 0 sein — der KoSIT-Validator lehnt die Rechnung sonst ab.

So beheben Sie den Fehler

Lassen Sie line.vat auf O-Positionen (und vat auf O-Nachlässen/-Zuschlägen) weg — ein gesetzter Satz fließt in die Steuerberechnung ein, obwohl für Kategorie O kein Satz ausgegeben wird.

Related rules

BR-46 — A VAT breakdown (BG-23) has no tax amount (BT-117).
BR-CO-17 — A VAT breakdown's tax amount (BT-117) does not equal its taxable amount (BT-116) multiplied by the category…
BR-DEC-20 — A VAT category tax amount (BT-117) uses more than 2 decimal places — EN 16931 allows at most 2.
BR-AE-09 — The tax amount (BT-117) of the reverse-charge (AE) breakdown must be 0.
BR-AF-09 — The tax amount (BT-117) of an IGIC (L) breakdown must equal its taxable amount (BT-116) multiplied by its…
BR-AG-09 — The tax amount (BT-117) of an IPSI (M) breakdown must equal its taxable amount (BT-116) multiplied by its…

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.