# BR-Z-03 Zero-rated document allowance requires a seller tax identifier

An invoice that contains a document level allowance (BG-20) whose document level allowance VAT category code (BT-95) is "Zero rated" shall contain the Seller VAT identifier (BT-31), the Seller tax registration identifier (BT-32) and/or the Seller tax representative VAT identifier (BT-63).

## Problem Description

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

## Context and Significance

This EN16931 rule is the counterpart of BR-Z-02 for document level allowances with category Z. In practice, the error occurs when a discount on zero-rated goods is exported at document level while the seller party carries no VAT identifier, tax number or tax representative.

## Solution

Provide the seller VAT identifier (BT-31), tax registration identifier (BT-32) or tax representative VAT identifier (BT-63) whenever a document level allowance uses category Z.

- [Validate XML](/en/xrechnung-validator?source=resource&rule=BR-Z-03)
- [Convert invoice](/en/pdf-to-xrechnung?source=resource&rule=BR-Z-03)

## Valid Examples

- Document allowance with category Z at 0 % and seller VAT identifier DE123456789 present

## Invalid Examples

- Document allowance with category Z but no BT-31, BT-32 or BT-63 on the seller party

## Code Examples

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

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

## Affected Fields

- [BT-31 Seller VAT identifier](/resources/xrechnung/bt-31-seller-vat-identifier)
- [BT-32 Seller tax registration identifier](/resources/xrechnung/bt-32-seller-tax-registration-identifier)
- [BT-63 Seller tax representative VAT identifier](/resources/xrechnung/bt-63-seller-tax-representative-vat-identifier)
- [BT-95 Document level allowance VAT category code](/resources/xrechnung/bt-95-document-level-allowance-vat-category-code)

## Related Rules

- [BR-Z-02](/resources/kosit-validator-errors/br-z-02-zero-rated-line-seller-vat-id)
- [BR-Z-04](/resources/kosit-validator-errors/br-z-04-zero-rated-charge-seller-vat-id)
- [BR-Z-06](/resources/kosit-validator-errors/br-z-06-zero-rated-allowance-rate-zero)

## 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.