# BR-15 Amount due for payment is required

An invoice shall have the Amount due for payment (BT-115), the outstanding amount the buyer has to pay.

## Problem Description

An invoice shall have the Amount due for payment (BT-115), the outstanding amount the buyer has to pay.

> **ERROR**: XRechnung 3.0

## Context and Significance

This is a core EN16931 rule; BT-115 is the figure the buyer actually pays, so no invoice may omit it.

## Solution

Add cac:LegalMonetaryTotal/cbc:PayableAmount equal to BT-112 minus prepaid amount (BT-113) plus rounding amount (BT-114).

- validate
- convert

## Valid Examples

- BT-115 = 1190.00 — nothing prepaid, so amount due equals gross total

## Invalid Examples

- cac:LegalMonetaryTotal has no cbc:PayableAmount element

## Code Examples

### Valid XML
```
<cac:LegalMonetaryTotal>
  <cbc:TaxInclusiveAmount currencyID="EUR">1190.00</cbc:TaxInclusiveAmount>
  <cbc:PayableAmount currencyID="EUR">1190.00</cbc:PayableAmount>
</cac:LegalMonetaryTotal>
```

### Invalid XML
```
<cac:LegalMonetaryTotal>
  <cbc:TaxExclusiveAmount currencyID="EUR">1000.00</cbc:TaxExclusiveAmount>
  <cbc:TaxInclusiveAmount currencyID="EUR">1190.00</cbc:TaxInclusiveAmount>
</cac:LegalMonetaryTotal>
```

## Affected Fields

- [BT-115 Amount due for payment](/resources/xrechnung/bt-115-amount-due-for-payment)

## Related Rules

- [BR-14](/resources/kosit-validator-errors/br-14-invoice-total-with-vat-required)
- [BR-CO-16](/resources/kosit-validator-errors/br-co-16-amount-due-for-payment-must-match)

## 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.