# BR-O-06 Category O document allowance must not carry a VAT rate

A document level allowance (BG-20) whose VAT category code (BT-95) is "Not subject to VAT" (O) shall not contain a Document level allowance VAT rate (BT-96).

## Problem Description

> **ERROR**: EN 16931 VAT category rule

## Context and Significance

Category O amounts are outside the scope of VAT, so a rate on a document level allowance is forbidden, even 0. In practice, the error occurs when a document level discount template always includes cbc:Percent.

## Solution

Delete cbc:Percent (BT-96) from the allowance cac:TaxCategory; category O carries no rate.

- [Validate XML](/en/xrechnung-validator?source=resource&rule=BR-O-06)
- [Convert invoice](/en/pdf-to-xrechnung?source=resource&rule=BR-O-06)

## Valid Examples

- Document allowance with cac:TaxCategory/cbc:ID = O and no cbc:Percent

## Invalid Examples

- Document allowance with cbc:ID = O but cbc:Percent = 0 present (BT-96)

## Code Examples

### Valid XML
```
<cac:AllowanceCharge>
  <cbc:ChargeIndicator>false</cbc:ChargeIndicator>
  <cbc:Amount currencyID="EUR">10.00</cbc:Amount>
  <cac:TaxCategory>
    <cbc:ID>O</cbc:ID>
    <cac:TaxScheme><cbc:ID>VAT</cbc:ID></cac:TaxScheme>
  </cac:TaxCategory>
</cac:AllowanceCharge>
```

### Invalid XML
```
<cac:AllowanceCharge>
  <cbc:ChargeIndicator>false</cbc:ChargeIndicator>
  <cbc:Amount currencyID="EUR">10.00</cbc:Amount>
  <cac:TaxCategory>
    <cbc:ID>O</cbc:ID>
    <cbc:Percent>0</cbc:Percent>
    <cac:TaxScheme><cbc:ID>VAT</cbc:ID></cac:TaxScheme>
  </cac:TaxCategory>
</cac:AllowanceCharge>
```

## Affected Fields

- [BT-95 Document level allowance VAT category code](/resources/xrechnung/bt-95-document-level-allowance-vat-category-code)
- [BT-96 Document level allowance VAT rate](/resources/xrechnung/bt-96-document-level-allowance-vat-rate)

## Related Rules

- [BR-O-01](/resources/kosit-validator-errors/br-o-01-not-subject-vat-breakdown-required)
- [BR-O-05](/resources/kosit-validator-errors/br-o-05-line-forbids-vat-rate)
- [BR-O-07](/resources/kosit-validator-errors/br-o-07-charge-forbids-vat-rate)

## 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.