{
  "id": "UBL-SR-45",
  "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": "Due Date shall occur maximum once",
  "statement_lang": "en",
  "context": "/ubl:Invoice | /cn:CreditNote",
  "test": "(count(cac:PaymentMeans/cbc:PaymentDueDate) <=1)",
  "meaning": "The due date shall occur at most once. The statement has no period and says shall. It is 33 characters. The flag is fatal. The context is the same string as BR-CO-18. The published test counts the payment due date. The count comparison has a space before <= and no space after it.",
  "fix": "Send at most one payment due date.",
  "example_fail": "The invoice has two payment due dates.",
  "example_pass": "The invoice has one payment due date, 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-45/",
  "source_retrieved": "2026-10-18",
  "last_verified": "2026-10-18"
}