{
  "id": "UBL-SR-15",
  "country": "EU",
  "syntax": "ubl",
  "group": "syntax",
  "severity": "fatal",
  "severity_note": "fatal, from the Flag column of the Peppol BIS Billing 3.0 UBL rules index retrieved 2026-10-18.",
  "spec": "Peppol BIS Billing 3.0, May 2026 release, EN 16931 model bound to UBL",
  "statement": "Buyer name shall occur maximum once",
  "statement_lang": "en",
  "context": "/ubl:Invoice | /cn:CreditNote",
  "test": "(count(cac:AccountingCustomerParty/cac:Party/cac:PartyLegalEntity/cbc:RegistrationName) <= 1)",
  "meaning": "The buyer name shall occur at most once. The statement has no period, says shall, and is 35 characters. The flag is fatal. The context is the same string as BR-CO-18. The published test counts the buyer legal-entity registration name. The comparison has a space before <= and a space after it.",
  "fix": "Send at most one buyer legal-entity registration name.",
  "example_fail": "The buyer legal entity has two registration names.",
  "example_pass": "The buyer legal entity has one registration name, or none.",
  "example_note": "Illustration of the condition in the official statement. Not an example published by the source.",
  "source_url": "https://docs.peppol.eu/poacc/billing/3.0/rules/ubl-tc434/UBL-SR-15/",
  "source_retrieved": "2026-10-18",
  "last_verified": "2026-10-18"
}