An invoice shall have an invoice number (ExchangedDocument/ID). (EN16931 BR-02)
Why Factur-X / CII invoices fail rule FX-HDR-001 (ERROR) and how to fix it: An invoice shall have an invoice number (ExchangedDocument/ID). (EN16931 BR-02)
What this rule checks
An invoice shall have an invoice number (ExchangedDocument/ID). (EN16931 BR-02)
Affected element: Invoice › Id.
Standard: EN 16931 / Factur-X (CII). Severity: ERROR.
Why your invoice is rejected
e-Invoicing platforms and buyers validate EN 16931 business rules after the XSD check. When this rule fails the invoice is rejected — even if the XML is otherwise well-formed — so it must be fixed before you send it.
How to fix it
Add Invoice › Id — it is mandatory for this Factur-X / EN 16931 profile.
Verify before you send
Upload your Factur-X / CII invoice to the validator to confirm this rule — and every other EN 16931 business rule — passes before your buyer or platform sees it.