BT-10Buyer reference
Official rule text
[BR-DE-15] The element "Buyer reference" (BT-10) must be transmitted.
Official text (German): Das Element "Buyer reference" (BT-10) muss übermittelt werden.
Why this error occurs
XRechnung makes the buyer reference (BT-10) mandatory because German public authorities route incoming invoices to the right office by the Leitweg-ID stored in this field. The rule checks cbc:BuyerReference (UBL) or ram:ApplicableHeaderTradeAgreement/ram:BuyerReference (CII) for a non-blank value. It is most often missing because the Leitweg-ID was put into the order reference, the buyer identifier or a note instead, or because the customer record has no Leitweg-ID at all.
How to fix it
In UBL add cbc:BuyerReference in the document header (after cbc:AccountingCost, before cac:InvoicePeriod and cac:OrderReference). In CII add ram:BuyerReference inside ram:ApplicableHeaderTradeAgreement, before ram:SellerTradeParty. Enter the Leitweg-ID exactly as the authority communicated it, e.g. 04011000-12345-67, without surrounding spaces. For private-sector buyers enter the reference they request (cost centre, contact), and if none is agreed, repeat the order number.
Example (valid)
<cbc:BuyerReference>04011000-12345-67</cbc:BuyerReference>What the validator checks
Checked element (context):
UBL
/ubl:Invoice | /cn:CreditNoteTest (XPath):
cbc:BuyerReference[boolean(normalize-space(.))]CII
/rsm:CrossIndustryInvoiceTest (XPath):
rsm:SupplyChainTradeTransaction/ram:ApplicableHeaderTradeAgreement/ram:BuyerReference[boolean(normalize-space(.))]Check your invoice
Drop your XML or PDF on the validator and every failed rule is linked to its page here. Free, no account, the file is not stored.
Same check via API:
curl -F file=@invoice.xml https://einvoicechecker.com/v1/validateRelated rules
BR-DE-1Payment instructions (BG-16) are missingBR-DE-2Seller contact (BG-6) is missingBR-DE-3Seller city (BT-37) is missingBR-DE-4The element "Seller post code" must be transmittedBR-DE-5Seller contact point (BT-41) is missingBR-DE-6Seller contact telephone number (BT-42) is missingBR-DE-7Seller contact email address (BT-43) is missingBR-DE-8The element "Buyer city" must be transmitted
Frequently asked questions
What does BR-DE-15 mean?
BR-DE-15 is a xrechnung rule: The element "Buyer reference" (BT-10) must be transmitted.
Will my invoice be rejected because of BR-DE-15?
Yes. BR-DE-15 is flagged "fatal"; validators (KoSIT, Peppol access points, the German ZRE/OZG-RE portals) reject the invoice until it is fixed.
Which formats does BR-DE-15 apply to?
XRechnung in UBL or CII syntax, including ZUGFeRD / Factur-X PDFs with the XRECHNUNG profile. Invoices to German public authorities (federal, state and municipal) must pass it. Syntax: UBL and CII.
Source: XRechnung 3.0.2, schematron 2.6.0 (KoSIT, September 2026). Catalogue generated from the official schematron on 2026-10-14.