DE-R-027: "Seller contact telephone number" should contain a valid…

StandardPeppol BIS Billing 3.0 country rules (NL, DE, IT, SE, DK, NO, GR, IS)CountryGermanySeverityWarning: the invoice is accepted but should be correctedSyntaxUBLBusiness terms

BT-42 Seller contact telephone number

Applies toOnly when the seller (or for some rules the buyer) is in the named country: the rule is triggered by the country code of the party. Dutch rules implement NLCIUS, German rules the XRechnung requirements inside Peppol.

Official rule text

[DE-R-027] "Seller contact telephone number" (BT-42) should contain a valid telephone number. A valid telephone should consist of 3 digits minimum.

Why this error occurs

The validator evaluates the XPath test above against the context element; the assertion is false for your file.

How to fix it

Compare your file with the rule text and the test expression, adjust the element named in the context, and validate again.

What the validator checks

Checked element (context):

UBL

(/ubl-invoice:Invoice/cac:AccountingSupplierParty/cac:Party/cac:Contact | /ubl-creditnote:CreditNote/cac:AccountingSupplierParty/cac:Party/cac:Contact)[$supplierCountryIsDE and $customerCountryIsDE]

Test (XPath):

matches(normalize-space(cbc:Telephone), $XR-TELEPHONE-REGEX)

Check your invoice

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Same check via API:

curl -F file=@invoice.xml https://einvoicechecker.com/v1/validate

Related rules

DE-R-006 The element "Seller contact telephone number" shall be provided
DE-R-001 An invoice shall contain information on "PAYMENT INSTRUCTIONS"
DE-R-002 The group "SELLER CONTACT" shall be provided
DE-R-003 The element "Seller city" shall be provided
DE-R-004 The element "Seller post code" shall be provided
DE-R-005 The element "Seller contact point" shall be provided
DE-R-007 The element "Seller contact email address" shall be provided
DE-R-008 The element "Buyer city" shall be provided

Frequently asked questions

What does DE-R-027 mean?

DE-R-027 is a peppol national rule: "Seller contact telephone number" (BT-42) should contain a valid telephone number. A valid telephone should consist of 3 digits minimum.

Will my invoice be rejected because of DE-R-027?

No. DE-R-027 is a warning: the invoice is accepted but the recipient sees the notice. Fix it anyway, warnings often become errors in later rule versions.

Which formats does DE-R-027 apply to?

Only when the seller (or for some rules the buyer) is in the named country: the rule is triggered by the country code of the party. Dutch rules implement NLCIUS, German rules the XRechnung requirements inside Peppol. Syntax: UBL.

Source: Peppol BIS Billing 3.0.20 national rules (November 2025). Catalogue generated from the official rule sets on 2026-10-15.

DE-R-027: "Seller contact telephone number" should contain a valid telephone number