# BR-36 Document level charge amount is required

Each Document level charge (BG-21) shall have a Document level charge amount (BT-99).

## Problem Description

Each Document level charge (BG-21) shall have a Document level charge amount (BT-99).

> **ERROR**: XRechnung 3.0

## Context and Significance

This rule comes from the EN16931 core semantic model enforced by the KoSIT XRechnung 3.0.2 Schematron, ensuring invoices carry the mandatory data needed for automated processing.

## Solution

Add cbc:Amount to the document level cac:AllowanceCharge where cbc:ChargeIndicator is true.

- validate
- convert

## Valid Examples

- BT-99 = 9.90 on a document level charge (e.g. freight)

## Invalid Examples

- Document charge with reason but no BT-99 amount

## Code Examples

### Valid XML
```
<cac:AllowanceCharge>
  <cbc:ChargeIndicator>true</cbc:ChargeIndicator>
  <cbc:AllowanceChargeReason>Freight</cbc:AllowanceChargeReason>
  <cbc:Amount currencyID="EUR">9.90</cbc:Amount>
</cac:AllowanceCharge>
```

### Invalid XML
```
<cac:AllowanceCharge>
  <cbc:ChargeIndicator>true</cbc:ChargeIndicator>
  <cbc:AllowanceChargeReason>Freight</cbc:AllowanceChargeReason>
</cac:AllowanceCharge>
```

## Affected Fields

- [BT-99 Document level charge amount](/resources/xrechnung/bt-99-document-level-charge-amount)

## Related Rules

- [BR-37](/resources/kosit-validator-errors/br-37-document-charge-vat-category-required)
- [BR-38](/resources/kosit-validator-errors/br-38-document-charge-reason-required)
- [BR-31](/resources/kosit-validator-errors/br-31-document-allowance-amount-required)

## 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.