Invoice UUID

A universally unique identifier for an instance of an Invoice or a Credit Note. The identifier MUST be a UUID version 5, calculated over the fixed namespace e0bc4ac8-b025-46e5-a76d-0c893fc3027e and a name formed from the Seller VAT identifier (BT-31), the invoice type code (BT-03), the invoice number (BT-01) and the invoice issue date (BT-02), each trimmed of leading and trailing whitespace and joined with a single space character. See the Invoice UUID calculation section of the technical documentation.