# BR-CL-04 Invoice currency code must use ISO 4217 alpha-3

The invoice currency code (BT-5) must be a three-letter code from ISO 4217 alpha-3.

## Problem Description

> **ERROR**: EN 16931 code-list rule (BR-CL)

## Context and Significance

BT-5 sets the currency of all amounts on the invoice. The rule fails when the currency is copied from PDF text ("Euro", "€"), when an ERP exports an internal code such as "EURO", or when the code is lowercase ("eur"). A wrong BT-5 usually also breaks the currencyID attributes (BR-CL-03). Example: an invoice in Swiss francs uses BT-5 = CHF, not "SFr.".

## Solution

Set BT-5 to a valid ISO 4217 alpha-3 code in capital letters, such as EUR (UBL: cbc:DocumentCurrencyCode; CII: ram:InvoiceCurrencyCode). Map the currency field of the ERP to the ISO code; do not use symbols, names or internal abbreviations.

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

## Valid Examples

- BT-5 = EUR
- BT-5 = CHF

## Invalid Examples

- BT-5 = EURO — internal code, not ISO 4217
- BT-5 = Euro — currency name, not a code
- BT-5 = eur — lowercase

## Code Examples

### Valid XML
```
<cbc:DocumentCurrencyCode>EUR</cbc:DocumentCurrencyCode>
```

### Invalid XML
```
<cbc:DocumentCurrencyCode>EURO</cbc:DocumentCurrencyCode>
```

## Affected Fields

- [BT-5 Invoice currency code](/resources/xrechnung/bt-5-invoice-currency-code)

## Related Rules

- [BR-CL-03](/resources/kosit-validator-errors/br-cl-03-iso-4217-currency-attribute)
- [BR-CL-05](/resources/kosit-validator-errors/br-cl-05-iso-4217-tax-currency)

## 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.