What it means
When the seller and the buyer are both in Germany, the invoice must give a buyer reference (BT-10). This is a text the buyer chooses so they can route the invoice internally. For public-sector buyers in Germany it carries the Leitweg-ID. A blank or spaces-only value counts as missing.
Why it matters
The buyer's system uses the reference to send the invoice to the right person or department. In the public sector the Leitweg-ID decides which authority receives it. Without a reference the invoice fails the check and is rejected.
How to fix it
Ask the buyer which reference they want on invoices. For a public body that is the Leitweg-ID. For a company it is usually a number or code such as a customer number, cost centre or order reference. In your invoicing software the field is usually called buyer reference, customer reference or Leitweg-ID, and sits with the customer details or the invoice header. Enter it there and export the invoice again.
The rule as published
Read the rule on the publisher's site
Business terms: BT-10
Where this rule applies
| Rule set | Version |
|---|---|
| Peppol BIS Billing 3.0 (invoice) | 2026.5 |
| Peppol BIS Billing 3.0 (credit note) | 2026.5 |
Check your file
Drop your e-invoice to see whether DE-R-015 still fails, and which other rules do.
Related rules
- BR-DE-15 Buyer reference (Leitweg-ID) is required
- DE-R-016 Seller needs a VAT number, tax number or tax representative
- DE-R-017 Use an invoice type code from the list for German parties
- DE-R-018 Cash discount (Skonto) must use the fixed payment terms format
- DE-R-019 A SEPA bank transfer should name a valid IBAN
- DE-R-020 A SEPA direct debit should name a valid IBAN to debit