# BR-07 Buyer name is required

An invoice shall contain the Buyer name (BT-44), the name under which the customer is registered or known.

## Problem Description

An invoice shall contain the Buyer name (BT-44), the name under which the customer is registered or known.

> **ERROR**: XRechnung 3.0

## Context and Significance

This is a core EN16931 rule; the invoice must clearly state who is being billed, so the buyer name is mandatory.

## Solution

Provide cac:AccountingCustomerParty/cac:Party/cac:PartyLegalEntity/cbc:RegistrationName with the buyer’s name.

- validate
- convert

## Valid Examples

- BT-44 = Beispiel Einkauf AG — buyer registration name populated

## Invalid Examples

- cac:PartyLegalEntity/cbc:RegistrationName is missing for the customer party

## Code Examples

### Valid XML
```
<cac:AccountingCustomerParty>
  <cac:Party>
    <cac:PartyLegalEntity>
      <cbc:RegistrationName>Beispiel Einkauf AG</cbc:RegistrationName>
    </cac:PartyLegalEntity>
  </cac:Party>
</cac:AccountingCustomerParty>
```

### Invalid XML
```
<cac:AccountingCustomerParty>
  <cac:Party>
    <cac:PartyLegalEntity>
      <cbc:CompanyID>DE987654321</cbc:CompanyID>
    </cac:PartyLegalEntity>
  </cac:Party>
</cac:AccountingCustomerParty>
```

## Affected Fields

- [BT-44 Buyer name](/resources/xrechnung/bt-44-buyer-name)

## Related Rules

- [BR-06](/resources/kosit-validator-errors/br-06-seller-name-required)
- [BR-10](/resources/kosit-validator-errors/br-10-buyer-postal-address-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.