Validation rules

UBL-SR-37 — UBL rule

An item price discount (BT-147) appears more than once — only one cac:Price/cac:AllowanceCharge with one cbc:Amount per line is allowed.

Rule: UBL-SR-37 — 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

The serializer emits at most one price-level AllowanceCharge per line, from invoice.lines[i].gross_price / price_discount.

How to fix it

Keep a single price-level AllowanceCharge per line, or model discounts as line allowances (BG-27).

UBL-SR-37 auf Deutsch — was bedeutet der Fehler?

Der KoSIT-Validator lehnt die Rechnung ab, weil ein Preisnachlass (BT-147) mehrfach vorkommt — nur ein cac:Price/cac:AllowanceCharge mit einem cbc:Amount je Position ist erlaubt.

So beheben Sie den Fehler

Behalten Sie genau einen Preis-Nachlass je Position — oder modellieren Sie Rabatte als Positionsnachlässe (BG-27).

Related rules

UBL-SR-36 — An invoice line carries more than one invoicing period (BG-26) — only one cac:InvoicePeriod per line is…
UBL-SR-35 — An invoice line references more than one purchase order line (BT-132) — only one OrderLineReference/LineID…
UBL-SR-39 — The project reference (BT-11) appears more than once — only one cac:ProjectReference with one cbc:ID is…
UBL-SR-34 — An invoice line carries more than one note (BT-127) — only one cbc:Note per cac:InvoiceLine is allowed.
UBL-SR-40 — The buyer trading name (BT-45) appears more than once — the customer party may carry only one PartyName/Name.
UBL-SR-33 — A supporting document (BG-24) carries more than one description (BT-123) — only one cbc:DocumentDescription…

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.