DE-R-031
A Peppol Germany national rule (DE-R-*) – applies when the invoice is sent over the Peppol network to a receiver in Germany.
What this error means
DE-R-031
When both seller and buyer are located in Germany and direct debit (BG-19) is used, the debited account identifier (BT-91) must be provided.
How to fix it
In cac:PaymentMandate provide the payer account (cac:PayerFinancialAccount/cbc:ID).