Validation rules

BR-41 — EN 16931 rule

An invoice line allowance (BG-27) has no allowance amount (BT-136).

Rule: BR-41 — official EN 16931 / XRechnung rule
Severity: error
Business term: BT-136 — Line allowance amount
Field in your JSON: invoice.lines[*].allowances
Detected by: tier 3 — KoSIT validator (authoritative)
Reachability: Only reachable when validating your own XML — normbill-generated documents cannot trigger it

The request schema requires amount (or base_amount + percent) on every line allowance and the serializer always writes cbc:Amount; the UBL schema makes the element mandatory too.

How to fix it

Add cbc:Amount to the line allowance.

BR-41 auf Deutsch — was bedeutet der Fehler?

Ein Positionsnachlass (BG-27) hat keinen Nachlassbetrag (BT-136).

So beheben Sie den Fehler

Ergänzen Sie cbc:Amount im Positionsnachlass.

Related rules

BR-DEC-24 — A line-level allowance amount (BT-136) has more than 2 decimal places.
BR-42 — A line-level allowance must state why it is granted (BT-139/BT-140).
BR-43 — An invoice line charge (BG-28) has no charge amount (BT-141).
BR-38 — A document-level charge must state what it is for (BT-104/BT-105).
BR-44 — A line-level charge must state what it is for (BT-144/BT-145).
BR-37 — A document-level charge needs a VAT category (BT-102); it cannot be inherited because the lines use more…

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.