# BR-S-03 Standard-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 "Standard 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-S-02 for document level allowances with category S. It fails even when no invoice line uses category S, as long as one document level allowance does. In practice, the error appears when a volume or loyalty discount is exported at document level with category S while the seller party carries no tax identifier.

## 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 S.

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

## Valid Examples

- Document allowance with category S at 19 % and seller VAT identifier DE123456789 present

## Invalid Examples

- Document allowance with category S 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>S</cbc:ID><cbc:Percent>19</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>S</cbc:ID><cbc:Percent>19</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-S-02](/resources/kosit-validator-errors/br-s-02-standard-rated-line-seller-vat-id)
- [BR-S-04](/resources/kosit-validator-errors/br-s-04-standard-rated-charge-seller-vat-id)
- [BR-S-06](/resources/kosit-validator-errors/br-s-06-standard-rated-allowance-rate-positive)

## 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.