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BR-DE-28 Seller contact email must have valid syntax and a single at sign

Under rule BR-DE-28 of the German XRechnung profile, the seller contact email address (BT-43) must be a syntactically valid electronic mail address conforming to standard RFC 5322 specifications. The string must contain exactly one "@" character separating the local user/mailbox name from a valid fully qualified domain name (e.g. "rechnung@lieferant.de"). It must not contain leading or trailing whitespace, illegal characters, multiple comma-separated addresses, or missing top-level domain extensions.

Problem Description

ERROR

German XRechnung rule (KoSIT, BR-DE) · XRechnung 3.0

Context and Significance

Automated receipt platforms use BT-43 to return validation failure reports (Prüfprotokolle). An unparseable email syntax immediately triggers Schematron error BR-DE-28.

Solution

In your invoicing or master data settings, verify that the contact email address is formatted correctly as a single valid address (e.g. "buchhaltung@unternehmen.de"). In UBL 2.1 syntax, populate <cbc:ElectronicMail> within <cac:AccountingSupplierParty><cac:Party><cac:Contact>. In UN/CEFACT CII syntax, populate <ram:URIID> within <ram:EmailURIUniversalCommunication> under <ram:SellerTradeParty><ram:DefinedTradeContact>. If multiple recipients need notification, configure email distribution lists or mail forwarding on your mail server instead of putting multiple addresses in BT-43.

Quick actions

Validate XMLConvert invoice

Valid Examples

  • BT-43 = "rechnungswesen@lieferant.de"
  • BT-43 = "billing.team@company.eu"

Invalid Examples

  • BT-43 = "rechnung@lieferant@de" (Malformed address containing multiple "@" characters)
  • BT-43 = "rechnung@lieferant, vertrieb@lieferant.de" (Multiple addresses separated by comma)
  • BT-43 = "rechnung.lieferant.de" (Address missing the "@" delimiter entirely)

Code Examples

Valid XML
<cac:Contact>
  <cbc:Name>Buchhaltung</cbc:Name>
  <cbc:Telephone>+49 30 1234567</cbc:Telephone>
  <cbc:ElectronicMail>buchhaltung@unternehmen.de</cbc:ElectronicMail>
</cac:Contact>
Invalid XML
<cac:Contact>
  <cbc:Name>Buchhaltung</cbc:Name>
  <cbc:Telephone>+49 30 1234567</cbc:Telephone>
  <cbc:ElectronicMail>rechnung@firma.de, vertrieb@firma.de</cbc:ElectronicMail>
</cac:Contact>

Affected Fields

BT-43 Seller contact email address
BG-6 Seller contact

Validation Tools

Official KoSIT Validator

Run the official KoSIT validator with the XRechnung configuration to check EN 16931 and XRechnung rules.

Convert PDF to XRechnung

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