Validation rules

BR-DE-22 — XRechnung rule

Two embedded attachments share the same filename — every attached document's filename must be unique within the invoice.

Rule: BR-DE-22 — official EN 16931 / XRechnung rule
Severity: error
Business term: BT-125 — Supporting document binary
Field in your JSON: invoice.supporting_documents[*].content_base64

How to fix it

Rename the duplicate attachment filenames in invoice.supporting_documents.

BR-DE-22 auf Deutsch — was bedeutet der Fehler?

Zwei eingebettete Anlagen tragen denselben Dateinamen — jeder Anlagen-Dateiname muss innerhalb der Rechnung eindeutig sein.

So beheben Sie den Fehler

Benennen Sie die doppelten Dateinamen in invoice.supporting_documents um.

Related rules

BR-DE-21 — The specification identifier (BT-24) is not syntactically an XRechnung customization id.
BR-DE-20 — The debited account identifier (BT-91) does not look like a valid IBAN — for SEPA direct debits (means code…
BR-DE-19 — The payment account identifier (BT-84) does not look like a valid IBAN — for SEPA credit transfers (means…
BR-DE-18 — A payment-terms line starting with # is not a valid Skonto segment — XRechnung requires the exact format…
BR-DE-26 — A corrected invoice (type_code 384) should reference the invoice it corrects (BT-25).
BR-DE-17 — This invoice type code is not recommended in XRechnung.

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.