# UBL-SR-31

> Document level charge reason shall occur maximum once

Checked against Peppol BIS Billing 3.0 2026.5

Canonical: https://einvoicecheck.eu/rules/ubl-sr-31

## Official rule text

Document level charge reason shall occur maximum once

## Why did my invoice fail UBL-SR-31?

A document-level charge (BG-21) may state one Charge reason text (BT-104), explaining why the extra amount is added (e.g. freight, packaging). EN 16931 allows at most one reason text per charge, so cbc:AllowanceChargeReason must not repeat within a single document-level charge (cbc:ChargeIndicator = true). A coded reason (BT-105) may also be present.

## Common causes

- Two cbc:AllowanceChargeReason elements in the same document-level charge block.
- A template concatenates additional descriptive text as a second reason element.
- Reason repeated per language within one charge.

## How do I fix it?

```
Within each document-level charge keep one reason: <cbc:AllowanceChargeReason>Freight</cbc:AllowanceChargeReason> and remove any duplicate.
```