# DE-R-006

> If both supplier and customer are located in Germany, the element "Seller contact telephone number" (BT-42) shall be provided.

Checked against Peppol BIS Billing 3.0 2026.5

Canonical: https://einvoicecheck.eu/rules/de-r-006

## Official rule text

If both supplier and customer are located in Germany, the element "Seller contact telephone number" (BT-42) shall be provided.