Validation rules

BR-AG-04 — EN 16931 rule

A document-level charge uses VAT category M (IPSI), which requires the seller VAT identifier (BT-31), the tax registration number (BT-32) or the VAT identifier of a seller tax representative (BT-63).

Rule: BR-AG-04 — official EN 16931 / XRechnung rule
Severity: error
Business term: BT-31 — Seller VAT identifier
Field in your JSON: invoice.seller.vat_id
Detected by: tier 3 — KoSIT validator (authoritative)
Reachability: Triggerable from your request JSON (generate & validate)

How to fix it

Set invoice.seller.vat_id or invoice.seller.tax_number.

BR-AG-04 auf Deutsch — was bedeutet der Fehler?

Ein Zuschlag auf Dokumentebene verwendet die Kategorie M (IPSI); dafür ist die USt-IdNr. (BT-31) oder Steuernummer (BT-32) des Verkäufers oder die USt-IdNr. seines Steuervertreters (BT-63) Pflicht.

So beheben Sie den Fehler

Setzen Sie invoice.seller.vat_id oder invoice.seller.tax_number.

Related rules

BR-DE-16 — A seller VAT identifier (BT-31), tax registration number (BT-32) or seller tax representative (BG-11) is…
BR-S-02 — The invoice has standard-rated (S) lines, which require the seller VAT identifier (BT-31), the tax…
BR-CO-26 — The seller carries none of: VAT identifier (BT-31), legal registration identifier (BT-30) or seller…
BR-CO-09 — A VAT identifier (seller BT-31, buyer BT-48, or tax representative BT-63) does not start with an ISO 3166-1…
BR-AF-02 — The invoice has IGIC (L) lines, which require the seller VAT identifier (BT-31), the tax registration number…
BR-AF-03 — A document-level allowance uses VAT category L (IGIC), which requires the seller VAT identifier (BT-31), the…

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.