# BH-LEITWEG-01 — Buyer reference not in Leitweg format

> https://billhorse.com/en/rules/bh-leitweg-01/

## What does this error mean?

The buyer reference (BT-10) doesn't match the usual Leitweg-ID pattern — fine for B2B; public bodies usually expect one.

## How to fix it

For public-sector invoices, request the Leitweg-ID from the buyer (pattern: 04011000-12345-03).