Validation rules

UBL-CR-646 — UBL rule

An invoice line contains cac:SubInvoiceLine. XRechnung prohibits sub-invoice lines — the KoSIT validator raises this from a warning to an error, so the document is rejected.

Rule: UBL-CR-646 — official EN 16931 / XRechnung rule
Severity: error
Detected by: tier 3 — KoSIT validator (authoritative)
Reachability: Only reachable when validating your own XML — normbill-generated documents cannot trigger it

Error via the KoSIT configuration's customLevel (CEN ships it as a warning). normbill lines are always flat, so generated XML never contains SubInvoiceLine.

How to fix it

Flatten the hierarchy: model every sub-line as its own top-level cac:InvoiceLine.

UBL-CR-646 auf Deutsch — was bedeutet der Fehler?

Der KoSIT-Validator lehnt die Rechnung ab, weil eine Rechnungsposition cac:SubInvoiceLine enthält. Die XRechnung verbietet Unterpositionen — die Validator-Konfiguration stuft diese Regel von einer Warnung zu einem Fehler hoch.

So beheben Sie den Fehler

Lösen Sie die Hierarchie auf: Modellieren Sie jede Unterposition als eigene cac:InvoiceLine auf oberster Ebene.

Related rules

UBL-CR-561 — An invoice line contains cac:TaxTotal. In EN 16931 VAT is broken down at document level only (BG-23) — lines…
UBL-CR-006 — cbc:IssueTime is present. The EN 16931 core model works with dates only (BT-2) — a time of day is not part…
UBL-CR-002 — cbc:UBLVersionID is present with a value other than 2.1. EN 16931 invoices are UBL 2.1 — omit the element or…
UBL-CR-001 — The document contains ext:UBLExtensions. Extensions are valid UBL but not part of the EN 16931 core model —…

Official sources

Every 422 from the API lists the rule id, the path in your request JSON, a plain-language message and a suggested fix — see the docs overview for the report format.

Or try it live: drop any XRechnung XML on the free validator — same KoSIT-backed report, no account.