# BR-CL-03 Currency attribute must use ISO 4217 alpha-3

The currencyID attribute on amount elements must be a three-letter code from ISO 4217 alpha-3.

## Problem Description

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

## Context and Significance

In UBL, every amount element (for example cbc:LineExtensionAmount, cbc:TaxAmount or cbc:PayableAmount) carries a currencyID attribute; in CII, only ram:TaxTotalAmount carries one. The rule fails when an export writes the symbol "€", the name "Euro", the numeric ISO code 978 or a lowercase "eur", because the check is case-sensitive. Example: currencyID="EUR" passes, currencyID="€" fails.

## Solution

Write a valid ISO 4217 alpha-3 code in capital letters, such as EUR, USD or CHF, in every currencyID attribute. Generate the attribute from the invoice currency code (BT-5), not from display text.

- [Validate XML](/en/xrechnung-validator?source=resource&rule=BR-CL-03)
- [Convert invoice](/en/pdf-to-xrechnung?source=resource&rule=BR-CL-03)

## Valid Examples

- currencyID="EUR" on a line amount
- currencyID="USD" on a VAT amount

## Invalid Examples

- currencyID="€" — symbol instead of code
- currencyID="978" — numeric ISO code instead of the alphabetic code
- currencyID="eur" — lowercase

## Code Examples

### Valid XML
```
<cbc:LineExtensionAmount currencyID="EUR">100.00</cbc:LineExtensionAmount>
```

### Invalid XML
```
<cbc:LineExtensionAmount currencyID="€">100.00</cbc:LineExtensionAmount>
```

## Affected Fields

- [currencyID attribute on amount elements](/resources/xrechnung)

## Related Rules

- [BR-CL-04](/resources/kosit-validator-errors/br-cl-04-iso-4217-invoice-currency)
- [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.