Rules / DE-R-T02 · Markdown

Peppol BIS Billing 3.0 · rule

DE-R-T02

Layer peppol·Checked against Peppol BIS Billing 3.0 2026.5

What does DE-R-T02 mean? If both supplier and customer are located in Germany, BT-124 "External document location" must contain an absolute URL with valid scheme.

Why did my invoice fail DE-R-T02?

On domestic German invoices, the External document location (BT-124) must be an absolute URL with a valid scheme (for example https://...). Relative paths or bare hostnames cannot be dereferenced by the receiver, so the link to the externally hosted supporting document would be useless. In UBL BT-124 is cac:AdditionalDocumentReference/cac:Attachment/cac:ExternalReference/cbc:URI.

Official rule text

If both supplier and customer are located in Germany, BT-124 "External document location" must contain an absolute URL with valid scheme.

Common causes

• A relative path like /docs/invoice-annex.pdf instead of a full URL
• Missing scheme, e.g. www.example.de/annex.pdf without https://
• A local file path (C:\...) or UNC path pasted into the URI field

How do I fix it?

<cac:AdditionalDocumentReference>
  <cbc:ID>Annex-1</cbc:ID>
  <cac:Attachment>
    <cac:ExternalReference>
      <cbc:URI>https://docs.example.de/invoices/2026/annex-1.pdf</cbc:URI>
    </cac:ExternalReference>
  </cac:Attachment>
</cac:AdditionalDocumentReference>