# BR-05 Invoice currency code must be present

An invoice must contain the invoice currency code (BT-5), such as EUR, so every amount can be interpreted consistently.

## Problem Description

An invoice must contain the invoice currency code (BT-5), such as EUR, so every amount can be interpreted consistently.

> **ERROR**: XRechnung 3.0

## Context and Significance

BT-5 is a base EN 16931 field. Missing currency breaks tax total, payable amount, and line amount validation before profile-specific rules run.

## Solution

Set BT-5 to the ISO 4217 currency used by the invoice totals and all line amounts.

- validate
- convert

## Valid Examples

- BT-5 = EUR
- DocumentCurrencyCode = USD for a USD invoice

## Invalid Examples

- BT-5 missing
- Currency written as free text outside the XML field

## Technical Details

### Affected Fields
BT-5 Invoice currency code

## Related Rules

- [BR-CO-10](/resources/kosit-validator-errors/br-co-10-sum-of-line-net-amounts-must-equal-line-total)
- [BR-CO-13](/resources/kosit-validator-errors/br-co-13-invoice-total-without-vat-must-match-totals-chain)

## 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.