DE-R-014
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-014
When both seller and buyer are located in Germany, the VAT category rate (BT-119) must be provided.
How to fix it
Fill in cbc:Percent in the VAT breakdown (cac:TaxSubtotal/cac:TaxCategory) – also for 0% categories.