# BR-19 Seller tax representative postal address is required when the party is present

The Seller tax representative postal address (BG-12) shall be provided when the Seller (BG-4) has a Seller tax representative party (BG-11).

## Problem Description

The Seller tax representative postal address (BG-12) shall be provided when the Seller (BG-4) has a Seller tax representative party (BG-11).

> **ERROR**: XRechnung 3.0

## Context and Significance

This is a core EN16931 conditional rule; the tax representative address is required for VAT jurisdiction whenever such a party is declared.

## Solution

When a cac:TaxRepresentativeParty group is present, add its cac:PostalAddress with at least the country code.

- validate
- convert

## Valid Examples

- cac:TaxRepresentativeParty present with a cac:PostalAddress containing a country

## Invalid Examples

- cac:TaxRepresentativeParty is present but has no cac:PostalAddress

## Code Examples

### Valid XML
```
<cac:TaxRepresentativeParty>
  <cac:PartyName>
    <cbc:Name>VAT Rep Services Ltd</cbc:Name>
  </cac:PartyName>
  <cac:PostalAddress>
    <cac:Country>
      <cbc:IdentificationCode>DE</cbc:IdentificationCode>
    </cac:Country>
  </cac:PostalAddress>
</cac:TaxRepresentativeParty>
```

### Invalid XML
```
<cac:TaxRepresentativeParty>
  <cac:PartyName>
    <cbc:Name>VAT Rep Services Ltd</cbc:Name>
  </cac:PartyName>
</cac:TaxRepresentativeParty>
```

## Affected Fields

- [BG-12 Seller tax representative postal address](/resources/xrechnung)
- [BG-11 Seller tax representative party](/resources/xrechnung)

## Related Rules

- [BR-18](/resources/kosit-validator-errors/br-18-tax-representative-name-required)
- [BR-20](/resources/kosit-validator-errors/br-20-tax-representative-country-code-required)

## 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.