The buyer reference is missing
The `Buyer reference` element (BT-10) must be provided. In the German public sector this is the recipient's *Leitweg-ID*.
Only the issuer holds this value: Factlint reports it and never fabricates it. Test your invoice to find out whether it is affected.
The message your validator prints
Copied verbatim from the sealed artefact: this is the exact sentence the check prints when this rule fails.
[BR-DE-15] Das Element "Buyer reference" (BT-10) muss übermittelt werden.
Quoted from schematron-xrechnung 3.0.2, licensed under Apache-2.0.
Common searches around this code
These phrases mirror what an integrator searches for: code, syntax, rule, business field and correction.
Test your file with this error in mind
Upload the invoice involved: the report will say whether this code appears, where it appears in the document, and whether Factlint can only report it or also fix it.
To automate this check in an ERP flow, call the validation API and link every returned code to its public page.
Why this error happens
This is the emblematic XRechnung rule, and the one that blocks the most first invoices. The Leitweg-ID is the routing address of the public body: without it the invoice does not reach the right department, and the portal refuses it before looking at the content at all. EN 16931 leaves BT-10 optional, which is why no non-German tool asks for it.
How to fix it
Ask your customer for the Leitweg-ID — it appears on the order or in their supplier portal. Its shape is standardised (`coarse-fine-checkdigit`) but its value cannot be derived from anything in the invoice. Factlint reports it as `needs_input` and never fabricates a default value.
XML correction example
<!-- ram:BuyerReference absent -->
<ram:BuyerReference>04011000-12345-67</ram:BuyerReference>