# BR-33 Document level allowance reason or reason code is required

Each Document level allowance (BG-20) shall have a Document level allowance reason (BT-97) or a Document level allowance reason code (BT-98).

## Problem Description

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

## Context and Significance

This is an EN 16931 core rule. The buyer must be able to see why the amount is reduced, for example a volume, loyalty or early-order discount. The error appears when an ERP exports only the allowance amount without a reason text or UNCL5189 code; provide at least one. If both are given, BR-CO-05 requires that they describe the same reason.

## Solution

Add cbc:AllowanceChargeReason text or cbc:AllowanceChargeReasonCode (UNCL5189) to the allowance; if both are given they must describe the same reason.

- [Validate XML](/en/xrechnung-validator?source=resource&rule=BR-33)
- [Convert invoice](/en/pdf-to-xrechnung?source=resource&rule=BR-33)

## Valid Examples

- BT-97 = "Volume discount"
- BT-98 = 95 (discount)

## Invalid Examples

- Document allowance with amount only, no reason or reason code

## Code Examples

### Valid XML
```
<cac:AllowanceCharge>
  <cbc:ChargeIndicator>false</cbc:ChargeIndicator>
  <cbc:AllowanceChargeReasonCode>95</cbc:AllowanceChargeReasonCode>
  <cbc:AllowanceChargeReason>Volume discount</cbc:AllowanceChargeReason>
  <cbc:Amount currencyID="EUR">20.00</cbc:Amount>
</cac:AllowanceCharge>
```

### Invalid XML
```
<cac:AllowanceCharge>
  <cbc:ChargeIndicator>false</cbc:ChargeIndicator>
  <cbc:Amount currencyID="EUR">20.00</cbc:Amount>
</cac:AllowanceCharge>
```

## Affected Fields

- [BT-97 Document level allowance reason](/resources/xrechnung/bt-97-document-level-allowance-reason)
- [BT-98 Document level allowance reason code](/resources/xrechnung/bt-98-document-level-allowance-reason-code)

## Related Rules

- [BR-31](/resources/kosit-validator-errors/br-31-document-allowance-amount-required)
- [BR-32](/resources/kosit-validator-errors/br-32-document-allowance-vat-category-required)
- [BR-CO-05](/resources/kosit-validator-errors/br-co-05-allowance-reason-code-match)

## 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.