Validation rules

BR-DE-27 — XRechnung rule

The seller contact phone number (BT-42) should contain at least three digits.

Rule: BR-DE-27 — official EN 16931 / XRechnung rule
Severity: warning
Business term: BT-42 — Seller contact phone
Field in your JSON: invoice.seller.contact.phone

How to fix it

Use a real phone number in invoice.seller.contact.phone.

BR-DE-27 auf Deutsch — was bedeutet der Fehler?

Die Telefonnummer der Ansprechperson (BT-42) soll mindestens drei Ziffern enthalten. Der Validator meldet eine Warnung.

So beheben Sie den Fehler

Verwenden Sie eine echte Telefonnummer in invoice.seller.contact.phone.

Related rules

BR-DE-6 — Seller contact phone number (BT-42) is missing.
BR-DE-26 — A corrected invoice (type_code 384) should reference the invoice it corrects (BT-25).
BR-DE-28 — The seller contact email (BT-43) does not look like an email address — exactly one @, at least two…
BR-DE-30 — Direct-debit information (BG-19) is present but the creditor identifier (BT-90) is missing.
BR-DE-31 — Direct-debit information (BG-19) is present but the debited account identifier (BT-91) is missing.
BR-DE-22 — Two embedded attachments share the same filename — every attached document's filename must be unique within…

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.