{
  "id": "BR-02",
  "country": "EU",
  "syntax": "ubl",
  "group": "document",
  "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 have an Invoice number (BT-1).",
  "statement_lang": "en",
  "context": "/ubl:Invoice | /cn:CreditNote",
  "test": "normalize-space(cbc:ID) != ''",
  "meaning": "An invoice must have an invoice number (BT-1). The published test checks that cbc:ID is not blank. The message says \"shall have\". It does not name a VAT category.",
  "fix": "Fill cbc:ID with a non-empty invoice number (BT-1).",
  "example_fail": "The invoice cbc:ID is missing or blank.",
  "example_pass": "The invoice cbc:ID contains a non-empty number.",
  "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/BR-02/",
  "source_retrieved": "2026-10-18",
  "last_verified": "2026-10-18"
}