DE-R-027:Invalid phone number format. The seller contact telephone number (BT-42) must contain at least 3 digits to be valid.
Fix: Invalid phone number format. The seller contact telephone number (BT-42) must contain at least 3 digits to be valid.
Invalid phone number format. The seller contact telephone number (BT-42) must contain at least 3 digits to be valid.
Engine Classification
Requires user confirmation before application
What is DE-R-027?
DE-R-027 is a warning validation rule defined in the PEPPOL_BIS specification (DEU national rules). It validates the Telephone element under Party > Contact in the UBL invoice XML.
The invoice may pass transmission, but this non-compliance can cause problems during tax audits or buyer-side processing.
Target path: //cac:AccountingSupplierParty/cac:Party/cac:Contact/cbc:Telephone
Why This Error Matters
Invoice will be rejected by German XRechnung validators. German e-invoicing has specific format requirements for payment details, contact information, and attachments.
DE-R-027 is a soft failure that can cause issues at the receiving end — tax audits, ERP processing, or VAT reconciliation mismatches.
Validator Behavior
- ·Generates validation warning
- ·Rejected by PEPPOL Access Points
- ·Rejected by XRechnung endpoints
- ·Error returned: DE-R-027
- ·Specification: PEPPOL_BIS
How to Fix It
Find the missing or empty field
Check cbc:Telephone at //cac:AccountingSupplierParty/cac:Party/cac:Contact/cbc:Telephone. This field is required but is either missing or empty.
Set the required value
Invalid phone number format. The seller contact telephone number (BT-42) must contain at least 3 digits to be valid.
Re-validate your invoice
Upload the corrected invoice to confirm DE-R-027 is resolved.
XML Example
Generic example based on the rule's target XPath. Your actual XML structure may differ.
<!-- Incorrect value --> <cbc:Telephone>INVALID</cbc:Telephone>
<!-- Corrected value --> <cbc:Telephone>VALID_VALUE</cbc:Telephone>
Technical Reference
//cac:AccountingSupplierParty/cac:Party/cac:Contact/cbc:TelephoneCommon Causes
- ·Seller telephone number format invalid
- ·BT-42 must contain at least 3 digits
- ·cbc:Telephone too short or contains only text
- ·Contact phone number not valid format
- ·Telephone field contains non-numeric or too few characters
Seeing this in production? The API handles DE-R-027 automatically. See the fix response →
Frequently Asked Questions
Invalid phone number format. The seller contact telephone number (BT-42) must contain at least 3 digits to be valid.
Invalid phone number format. The seller contact telephone number (BT-42) must contain at least 3 digits to be valid. You can also use Invoice Navigator's compliance engine to correct this automatically in your pipeline.
DE-R-027 is a warning that may not always cause rejection, but indicates a compliance issue.
Many instances of DE-R-027 can be automatically corrected using Invoice Navigator's compliance engine. The fix is applied in your pipeline with full audit evidence.
Related Content
Last updated: 14 April 2026
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