{
  "id": "UBL-SR-55",
  "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": "An Invoice shall contain maximum one Payment Mandate (BG-19).",
  "statement_lang": "en",
  "context": "/ubl:Invoice | /cn:CreditNote",
  "test": "count(cac:PaymentMeans/cac:PaymentMandate) <= 1",
  "meaning": "An invoice shall contain at most one payment mandate. The statement ends with a period and says shall. It is 61 characters. The flag is fatal. The context is an invoice or a credit note. The published test does not wrap the count in parentheses. It counts the payment mandate. The count comparison has a space before <= and a space after it.",
  "fix": "Send at most one payment mandate.",
  "example_fail": "An invoice has two payment mandates.",
  "example_pass": "An invoice has one payment mandate, 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-55/",
  "source_retrieved": "2026-10-18",
  "last_verified": "2026-10-18"
}