# BR-CL-14 Country codes must use ISO 3166-1

Country codes in an invoice, such as the seller (BT-40) and buyer (BT-55) country, must be coded using ISO 3166-1 alpha-2.

## Problem Description

Country codes in an invoice, such as the seller (BT-40) and buyer (BT-55) country, must be coded using ISO 3166-1 alpha-2.

> **ERROR**: XRechnung 3.0

## Context and Significance

This EN16931 core code-list rule keeps postal-address countries interoperable across borders.

## Solution

Use the two-letter ISO 3166-1 alpha-2 code, e.g. DE for Germany, FR for France, IT for Italy.

- validate
- convert

## Valid Examples

- BT-40 = DE
- BT-55 = FR

## Invalid Examples

- BT-40 = GER — three letters, not ISO 3166-1 alpha-2
- BT-40 = Germany — country name

## Code Examples

### Valid XML
```
<cac:PostalAddress>
  <cac:Country>
    <cbc:IdentificationCode>DE</cbc:IdentificationCode>
  </cac:Country>
</cac:PostalAddress>
```

### Invalid XML
```
<cac:PostalAddress>
  <cac:Country>
    <cbc:IdentificationCode>GER</cbc:IdentificationCode>
  </cac:Country>
</cac:PostalAddress>
```

## Affected Fields

- [BT-40 Seller country code](/resources/xrechnung/bt-40-seller-country-code)
- [BT-55 Buyer country code](/resources/xrechnung/bt-55-buyer-country-code)

## Related Rules

- [BR-CL-15](/resources/kosit-validator-errors/br-cl-15-iso-3166-item-origin-country)

## 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.