# BR-S-04 Standard-rated document charge requires a seller tax identifier

An invoice that contains a document level charge (BG-21) whose document level charge VAT category code (BT-102) 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 and BR-S-03 for document level charges with category S. A charge alone, such as freight or packaging, makes a seller tax identifier mandatory. In practice, the error appears on invoices whose lines use another category but whose shipping charge is exported with category S.

## Solution

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

- [Validate XML](/en/xrechnung-validator?source=resource&rule=BR-S-04)
- [Convert invoice](/en/pdf-to-xrechnung?source=resource&rule=BR-S-04)

## Valid Examples

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

## Invalid Examples

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

## Code Examples

### Valid XML
```
<cac:AllowanceCharge>
  <cbc:ChargeIndicator>true</cbc:ChargeIndicator>
  <cbc:Amount currencyID="EUR">15.00</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>true</cbc:ChargeIndicator>
  <cbc:Amount currencyID="EUR">15.00</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-102 Document level charge VAT category code](/resources/xrechnung/bt-102-document-level-charge-vat-category-code)

## Related Rules

- [BR-S-02](/resources/kosit-validator-errors/br-s-02-standard-rated-line-seller-vat-id)
- [BR-S-03](/resources/kosit-validator-errors/br-s-03-standard-rated-allowance-seller-vat-id)
- [BR-S-07](/resources/kosit-validator-errors/br-s-07-standard-rated-charge-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.