# BR-50 Credit transfer requires a payment account identifier

A Payment account identifier (BT-84) shall be present if Credit transfer (BG-17) information is provided in the Invoice.

## Problem Description

> **ERROR**: EN 16931 core business rule (CEN)

## Context and Significance

This is an EN 16931 core rule. BR-50 checks the credit transfer group (BG-17): once cac:PayeeFinancialAccount is present, its cbc:ID (BT-84), usually the IBAN, must not be empty. The difference from BR-61: BR-50 fires on an account group that is present but empty, while BR-61 fires when payment means code 30 or 58 has no account identifier at all. A typical cause is an export that writes an empty account element because the IBAN field in the master data is blank. In CII, BT-84 is ram:PayeePartyCreditorFinancialAccount/ram:IBANID or ram:ProprietaryID.

## Solution

Provide cac:PayeeFinancialAccount/cbc:ID, usually the IBAN, for every credit transfer payment means group.

- [Validate XML](/en/xrechnung-validator?source=resource&rule=BR-50)
- [Convert invoice](/en/pdf-to-xrechnung?source=resource&rule=BR-50)

## Valid Examples

- BT-84 = DE89370400440532013000 with credit transfer

## Invalid Examples

- cac:PayeeFinancialAccount is present but its cbc:ID is empty or missing (<cac:PayeeFinancialAccount/>)

## Code Examples

### Valid XML
```
<cac:PaymentMeans>
  <cbc:PaymentMeansCode>58</cbc:PaymentMeansCode>
  <cac:PayeeFinancialAccount>
    <cbc:ID>DE89370400440532013000</cbc:ID>
  </cac:PayeeFinancialAccount>
</cac:PaymentMeans>
```

### Invalid XML
```
<cac:PaymentMeans>
  <cbc:PaymentMeansCode>58</cbc:PaymentMeansCode>
  <cac:PayeeFinancialAccount/>
</cac:PaymentMeans>
```

## Affected Fields

- [BT-84 Payment account identifier](/resources/xrechnung/bt-84-payment-account-identifier)

## Related Rules

- [BR-49](/resources/kosit-validator-errors/br-49-payment-means-type-code-required)
- [BR-61](/resources/kosit-validator-errors/br-61-credit-transfer-account-required)

## 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.