# BR-41 Invoice line allowance amount is required

Each Invoice line allowance (BG-27) shall have an Invoice line allowance amount (BT-136).

## Problem Description

> **ERROR**: EN 16931 core business rule (CEN)

## Context and Significance

This is an EN 16931 core rule. An invoice line allowance (BG-27) lowers the invoice line net amount (BT-131); without its amount the line calculation cannot be checked, which often also triggers a line arithmetic error. The UBL schema already requires cbc:Amount, so BR-41 is mainly reported for CII lines whose allowance holds only a percentage or a reason, for example a discount rate taken over from a price list.

## Solution

Add cbc:Amount to the invoice line cac:AllowanceCharge where cbc:ChargeIndicator is false (CII: ram:ActualAmount in ram:SpecifiedLineTradeSettlement/ram:SpecifiedTradeAllowanceCharge). If only a percentage is known, calculate the amount as base amount × percentage ÷ 100.

- [Validate XML](/en/xrechnung-validator?source=resource&rule=BR-41)
- [Convert invoice](/en/pdf-to-xrechnung?source=resource&rule=BR-41)

## Valid Examples

- BT-136 = 3.00 on an invoice line allowance

## Invalid Examples

- CII line allowance with a reason and a percentage but no ram:ActualAmount (BT-136); in UBL a cac:AllowanceCharge without cbc:Amount is already an XML schema error

## Code Examples

### Valid XML
```
<ram:SpecifiedLineTradeSettlement>
  <ram:SpecifiedTradeAllowanceCharge>
    <ram:ChargeIndicator>
      <udt:Indicator>false</udt:Indicator>
    </ram:ChargeIndicator>
    <ram:CalculationPercent>10.00</ram:CalculationPercent>
    <ram:BasisAmount>30.00</ram:BasisAmount>
    <ram:ActualAmount>3.00</ram:ActualAmount>
    <ram:Reason>Damaged packaging</ram:Reason>
  </ram:SpecifiedTradeAllowanceCharge>
</ram:SpecifiedLineTradeSettlement>
```

### Invalid XML
```
<ram:SpecifiedLineTradeSettlement>
  <ram:SpecifiedTradeAllowanceCharge>
    <ram:ChargeIndicator>
      <udt:Indicator>false</udt:Indicator>
    </ram:ChargeIndicator>
    <ram:CalculationPercent>10.00</ram:CalculationPercent>
    <ram:BasisAmount>30.00</ram:BasisAmount>
    <ram:Reason>Damaged packaging</ram:Reason>
  </ram:SpecifiedTradeAllowanceCharge>
</ram:SpecifiedLineTradeSettlement>
```

## Affected Fields

- [BT-136 Invoice line allowance amount](/resources/xrechnung/bt-136-invoice-line-allowance-amount)

## Related Rules

- [BR-42](/resources/kosit-validator-errors/br-42-line-allowance-reason-required)
- [BR-43](/resources/kosit-validator-errors/br-43-line-charge-amount-required)

## Validation Tools

- [Official KoSIT Validator](https://github.com/itplr-kosit/validator): Run the official KoSIT validator with the XRechnung configuration to check EN 16931 and XRechnung rules.
- [Convert PDF to XRechnung](/pdf-to-xrechnung): Find validation errors during conversion and review each correction.

## Related Resources

- [Official Specification](https://docs.peppol.eu/poacc/billing/3.0/rules/ubl-tc434/)
- [Test Suite](https://github.com/itplr-kosit/xrechnung-testsuite)
- [All validation errors](/resources/kosit-validator-errors): Overview of the EN 16931, XRechnung and Peppol validation rules explained here.