BR-42Each Invoice line allowance (BG-27) shall have an Invoice line allowance reason (BT-139) or an Invoice line allowance reason code (BT-140).

Why does BR-42 happen?

This rule and BR-CO-23 are one check written twice in the norm. They always report together: a single missing reason produces two error codes, not two errors.

What the validator checks

The expression the official KoSIT rule set evaluates — not paraphrased, but read from the Schematron file it ships. UBL and CII address different document trees, so the same rule reads differently in each.

UBL

exists(cbc:AllowanceChargeReason) or exists(cbc:AllowanceChargeReasonCode)

CII

(../ram:Reason) or (../ram:ReasonCode)

Source: rule set v2026-08-31

How do you fix BR-42?

Set cbc:AllowanceChargeReason or cbc:AllowanceChargeReasonCode inside cac:AllowanceCharge in UBL, ram:Reason or ram:ReasonCode in CII. That clears BR-CO-23 at the same time. Choose the code and BR-CL-19 applies as well: only 19 values from UNCL 5189 are permitted for it. The plain text is bound to no list — write that if in doubt. On the code and the text agreeing, see BR-CO-07 — a rule the validator never reports.

<cac:InvoiceLine>
  <cbc:ID>1</cbc:ID>
  <cac:AllowanceCharge>
    <cbc:ChargeIndicator>false</cbc:ChargeIndicator>
    <cbc:Amount currencyID="EUR">50.00</cbc:Amount>
  </cac:AllowanceCharge>
</cac:InvoiceLine>

<cac:InvoiceLine>
  <cbc:ID>1</cbc:ID>
  <cac:AllowanceCharge>
    <cbc:ChargeIndicator>false</cbc:ChargeIndicator>
    <cbc:AllowanceChargeReason>Mengenrabatt</cbc:AllowanceChargeReason>
    <cbc:Amount currencyID="EUR">50.00</cbc:Amount>
  </cac:AllowanceCharge>
</cac:InvoiceLine>