BT-87Payment card primary account number
Official rule text
[BR-51] In accordance with card payments security standards an invoice should never include a full card primary account number (BT-87). At the moment PCI Security Standards Council has defined that the first 6 digits and last 4 digits are the maximum number of digits to be shown.
Why this error occurs
The element or combination is not allowed in this context. The file contains something the standard forbids: an element that must not be repeated, a value that contradicts another field, or data that belongs to a different profile.
How to fix it
Remove the offending element or make the two fields consistent as described in the rule text. If your software adds the element automatically, check for a profile setting (e.g. "EN 16931" vs "EXTENDED") or an export option that suppresses it.
What the validator checks
Checked element (context):
UBL
cac:PaymentMeans/cac:CardAccount/cbc:PrimaryAccountNumberIDTest (XPath):
string-length(normalize-space(.))<=10CII
//ram:ApplicableTradeSettlementFinancialCardTest (XPath):
string-length(ram:ID)<=10
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-01Specification identifier (BT-24) is missingBR-02Invoice number (BT-1) is missingBR-03Invoice issue date (BT-2) is missingBR-04Invoice type code (BT-3) is missingBR-05Invoice currency code (BT-5) is missingBR-06Seller name (BT-27) is missingBR-07Buyer name (BT-44) is missingBR-08Seller postal address is missing
Frequently asked questions
What does BR-51 mean?
BR-51 is a en 16931 core rule: In accordance with card payments security standards an invoice should never include a full card primary account number (BT-87). At the moment PCI Security Standards Council has defined that the first 6 digits and last 4 digits are the maximum number of digits to be shown.
Will my invoice be rejected because of BR-51?
Yes. BR-51 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-51 apply to?
Every EN 16931 invoice: XRechnung, ZUGFeRD 2.x / Factur-X (profiles EN 16931, EXTENDED, XRECHNUNG), Peppol BIS Billing 3.0, and national CIUS such as the Dutch NLCIUS or the Italian/Spanish profiles. Syntax: UBL and CII.
Source: EN 16931-1:2017 schematron (CEN TC434, via Peppol BIS 3.0.20). Catalogue generated from the official schematron on 2026-10-14.