{
  "id": "UBL-SR-37",
  "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": "Item price discount shall occur maximum once",
  "statement_lang": "en",
  "context": "cac:InvoiceLine | cac:CreditNoteLine",
  "test": "(count(cac:Price/cac:AllowanceCharge/cbc:Amount) <= 1)",
  "meaning": "The item price discount shall occur at most once. The statement has no period and says shall. It is 44 characters. It says discount. The flag is fatal. The context is an invoice line or a credit note line. The published test counts cac:Price/cac:AllowanceCharge/cbc:Amount. The count comparison has a space before <= and a space after it.",
  "fix": "On an invoice line or a credit note line, send at most one item price discount.",
  "example_fail": "An invoice line has two item price discounts.",
  "example_pass": "An invoice line has one item price discount, 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-37/",
  "source_retrieved": "2026-10-18",
  "last_verified": "2026-10-18"
}