Validation rules

NB-VAT-RATE

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

Rule
NB-VAT-RATEnormbill 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.

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.