# BR-DE-6 Seller name must be provided

The seller's name must be provided on the invoice.

## Problem Description

The seller's name must be provided on the invoice.

> **ERROR**: XRechnung 3.0

## Context and Significance

The seller name is required to clearly identify the invoice issuer. Use the registered legal name (including legal form like GmbH/AG) to avoid mismatches with registry or contracting data.

## Solution

Add the seller's name to the invoice.

## Valid Examples

- Mustermann GmbH
- ABC Technologies AG

## Invalid Examples

- Seller name missing
- Only whitespace

## Code Examples

### Valid XML
```
<cac:AccountingSupplierParty>
  <cac:Party>
    <cac:PartyName>
      <cbc:Name>Mustermann GmbH</cbc:Name>
    </cac:PartyName>
  </cac:Party>
</cac:AccountingSupplierParty>
```

### Invalid XML
```
<cac:AccountingSupplierParty>
  <cac:Party>
    <!-- Missing cac:PartyName/cbc:Name -->
  </cac:Party>
</cac:AccountingSupplierParty>
```

## Technical Details

### Affected Fields
Seller Name

## Related Rules

- [BR-DE-2](/resources/kosit-validator-errors/br-de-2-seller-contact-must-be-provided)
- [BR-DE-3](/resources/kosit-validator-errors/br-de-3-seller-city-must-be-provided)
- [BR-DE-4](/resources/kosit-validator-errors/br-de-4-seller-postal-code-must-be-provided)
- [BR-DE-5](/resources/kosit-validator-errors/br-de-5-seller-country-must-be-provided)

## 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.