# BR-O-04 Category O document charge forbids VAT identifiers

An invoice with a document level charge (BG-21) whose Document level charge VAT category code (BT-102) is "Not subject to VAT" (O) shall not contain the Seller VAT identifier (BT-31), the Seller tax representative VAT identifier (BT-63) or the Buyer VAT identifier (BT-48).

## Problem Description

An invoice with a document level charge (BG-21) whose Document level charge VAT category code (BT-102) is "Not subject to VAT" (O) shall not contain the Seller VAT identifier (BT-31), the Seller tax representative VAT identifier (BT-63) or the Buyer VAT identifier (BT-48).

> **ERROR**: XRechnung 3.0

## Context and Significance

Category O charges fall outside VAT, so the invoice must not present any VAT registration number for the parties.

## Solution

Remove the VAT identifiers BT-31, BT-63 and BT-48 whenever a document level charge uses category O.

- validate
- convert

## Valid Examples

- Document charge with BT-102 = O and no VAT identifier on any party

## Invalid Examples

- Document charge with BT-102 = O but Seller VAT identifier BT-31 = DE123456789 present

## Code Examples

### Valid XML
```
<cac:AllowanceCharge>
  <cbc:ChargeIndicator>true</cbc:ChargeIndicator>
  <cbc:Amount currencyID="EUR">15.00</cbc:Amount>
  <cac:TaxCategory><cbc:ID>O</cbc:ID></cac:TaxCategory>
</cac:AllowanceCharge>
<cac:AccountingSupplierParty>
  <cac:Party/>
</cac:AccountingSupplierParty>
```

### Invalid XML
```
<cac:AllowanceCharge>
  <cbc:ChargeIndicator>true</cbc:ChargeIndicator>
  <cbc:Amount currencyID="EUR">15.00</cbc:Amount>
  <cac:TaxCategory><cbc:ID>O</cbc:ID></cac:TaxCategory>
</cac:AllowanceCharge>
<cac:AccountingSupplierParty>
  <cac:Party>
    <cac:PartyTaxScheme>
      <cbc:CompanyID>DE123456789</cbc:CompanyID>
      <cac:TaxScheme><cbc:ID>VAT</cbc:ID></cac:TaxScheme>
    </cac:PartyTaxScheme>
  </cac:Party>
</cac:AccountingSupplierParty>
```

## Affected Fields

- [BT-31 Seller VAT identifier](/resources/xrechnung/bt-31-seller-vat-identifier)
- [BT-63 Seller tax representative VAT identifier](/resources/xrechnung/bt-63-seller-tax-representative-vat-identifier)
- [BT-48 Buyer VAT identifier](/resources/xrechnung/bt-48-buyer-vat-identifier)
- [BT-102 Document level charge VAT category code](/resources/xrechnung/bt-102-document-level-charge-vat-category-code)

## Related Rules

- [BR-O-01](/resources/kosit-validator-errors/br-o-01-not-subject-vat-breakdown-required)
- [BR-O-02](/resources/kosit-validator-errors/br-o-02-line-forbids-vat-identifiers)
- [BR-O-03](/resources/kosit-validator-errors/br-o-03-allowance-forbids-vat-identifiers)

## Validation Tools

- [Official KoSIT Validator](https://erechnungsvalidator.service-bw.de/): Validate your XRechnung files against all BR-DE rules.
- [Convert PDF to XRechnung](/pdf-to-xrechnung): Automatic validation error fixes when converting.

## Related Resources

- [Official Specification](https://xeinkauf.de/xrechnung/)
- [Test Suite](https://github.com/itplr-kosit/xrechnung-testsuite)
- [Complete Error List](/resources/kosit-validator-errors): Overview of all German XRechnung validation rules.