BR-DE-28:Seller Contact Email Must Have Valid Format
Contact email addresses must be valid email format. The email must contain proper structure with username, @ symbol, and domain. Invalid email addresses fail schema validation.
Engine Classification
Add payment due date if missing for XRechnung compliance
Confidence: 80% · Applied automatically in pipeline
What is BR-DE-28?
BR-DE-28 is a fatal validation rule defined in the XRechnung (Germany) specification (DEU national rules). It validates the PaymentDueDate element in the UBL invoice XML.
When this rule fires, the invoice is non-compliant and will be rejected by Peppol access points and national validation services. The sending system receives a rejection response and the invoice does not reach the buyer.
Target path: //cac:PaymentMeans/cbc:PaymentDueDate
Why This Error Matters
Invoice will be rejected by XRechnung validation. Invalid email format fails schema validation and prevents proper contact information storage.
BR-DE-28 is a hard failure. Invoices that trigger this rule are rejected at the access point and never reach the recipient. In Peppol networks, this means your sending system receives an MLR (Message Level Response) with a rejection status. The invoice must be corrected and re-sent, adding delay to your payment cycle.
Invoice Navigator can automatically correct this error in your pipeline. The fix is applied with full audit evidence, so your compliance trail remains intact.
Validator Behavior
- ·Causes invoice rejection
- ·Rejected by XRechnung endpoints
- ·Error returned: BR-DE-28
- ·Specification: XRechnung (Germany)
How to Fix It
Before / After
<Invoice> <!-- Issue: XRechnung requires seller contact email to have valid format --> </Invoice>
<Invoice> <!-- Issue resolved per XRechnung (Germany) --> </Invoice>
Technical Reference
//cac:PaymentMeans/cbc:PaymentDueDateCommon Causes
- ·Typo in email address (missing @, double dots)
- ·Invalid domain format
- ·Spaces accidentally included in email
- ·Placeholder text left instead of real email
- ·Copy/paste error corrupted the email address
Seeing this in production? The API handles BR-DE-28 automatically. See the fix response →
Frequently Asked Questions
This error occurs when the seller contact email (BT-43) has an invalid format. Common issues include missing @ symbol, spaces in the email, dots at the start or end, or too few characters before/after the @ symbol.
Enter a properly formatted email address like kontakt@muster.de. Remove any spaces, ensure there is exactly one @ symbol, and verify the email does not start or end with a dot.
XRechnung requires: exactly one @ symbol, at least 2 characters before and after @, no spaces, no dots at the start or end, and no dot or space immediately before the @ symbol.
XRechnung requires machine-readable email addresses for automated processing. Invalid formats would break contact information storage and automated communication systems.
Related Errors
Last updated: 27 February 2026
Handle BR-DE-28 Automatically in Your Pipeline
The compliance engine auto-remediates this error with controlled safety policies and evidence pack generation.