DE-R-006: The element "Seller contact telephone number" shall be…

StandardPeppol BIS Billing 3.0 country rules (NL, DE, IT, SE, DK, NO, GR, IS)CountryGermanySeverityError: the invoice is rejectedSyntaxUBLBusiness 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-006] The element "Seller contact telephone number" (BT-42) shall be provided.

Why this error occurs

The element is mandatory in this standard but is missing or empty in your file. Typical causes: the field is not filled in the invoicing software, the ERP export does not map it, or the element is present but contains only whitespace.

How to fix it

Add the element with a non-empty value at the position given by the context above. Check the master data (seller, buyer, payment) in your invoicing software; most tools expose the field under the business term name shown here. Re-validate after the change.

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):

cbc:Telephone[boolean(normalize-space(.))]

Check your invoice

Drop your XML or PDF on the validator and every failed rule is linked to its page here. Free, no account, the file is not stored.

Check your invoice →

Same check via API:

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

Related rules

DE-R-027 "Seller contact telephone number" should contain a valid telephone number
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-006 mean?

DE-R-006 is a peppol national rule: The element "Seller contact telephone number" (BT-42) shall be provided.

Will my invoice be rejected because of DE-R-006?

Yes. DE-R-006 is flagged "fatal"; validators (KoSIT, Peppol access points, the German ZRE/OZG-RE portals, KSeF) reject the invoice until it is fixed.

Which formats does DE-R-006 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-006: The element "Seller contact telephone number" shall be provided