Validation rules

NB-VAT-RATE — normbill pre-flight check

A line has neither a VAT rate nor a VAT category — the category cannot be determined.

Rule: NB-VAT-RATE — normbill pre-flight check (no single official rule id applies)
Severity: error
Business term: BT-152 — Line VAT rate
Field in your JSON: invoice.lines[*].vat

How to fix it

Set line.vat (e.g. 19) or an explicit line.vat_category.

NB-VAT-RATE auf Deutsch — was bedeutet der Fehler?

Eine Position hat weder einen Umsatzsteuersatz noch eine Umsatzsteuer-Kategorie — die Kategorie lässt sich nicht bestimmen.

So beheben Sie den Fehler

Setzen Sie line.vat (z. B. 19) oder explizit line.vat_category.

NB-* checks run before generation to catch problems the official rule set would only report indirectly. The authoritative KoSIT validation still has the final word on conformance.

Related rules

BR-S-05 — A standard-rated (S) line must have a VAT rate greater than zero.
BR-Z-05 — A zero-rated (Z) line must have a VAT rate of exactly 0.
BR-E-05 — A VAT-exempt (E) line must have a VAT rate of 0.
BR-AE-05 — A reverse-charge (AE) line must have a VAT rate of 0.
BR-O-05 — A line "not subject to VAT" (O) must not carry a VAT rate.
BR-IC-05 — An intra-community supply (K) line must have a VAT rate of exactly 0.

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.