BT-10Buyer reference

Mandatory on every XRechnung, including B2B. For invoices to a German public authority this is the Leitweg-ID, which routes the invoice to the right office; in B2B it carries whatever reference the buyer asked for, an order number for instance. Only checked for being non-empty — the rule set never looks at the Leitweg-ID’s structure or check digit.

XML element (UBL)
cbc:BuyerReference
XML element (CII)
ram:BuyerReference

Written and checked against the official KoSIT rule set by Dmytro Yalanskyi, NormAPI.

Validation rules for this field

Rules from the official KoSIT rule set that check this field — derived automatically from the written explanations, not hand-maintained.

NormAPI provides technical validation, not tax or legal advice.