# UBL-SR-37

Quoted from a public specification. This page is not a validator, and it is not tax, legal, or accounting advice.

- Country: EU
- Syntax: UBL
- Severity: fatal
- Statement language: en
- Last verified: 2026-10-18

## Official statement

> Item price discount shall occur maximum once

Source: https://docs.peppol.eu/poacc/billing/3.0/rules/ubl-tc434/UBL-SR-37/

Peppol BIS Billing 3.0, May 2026 release, EN 16931 model bound to UBL

Severity note: fatal, from the Flag column of the Peppol BIS Billing 3.0 UBL rules index retrieved 2026-10-18.

## Plain-language reading

The item price discount shall occur at most once. The statement has no period and says shall. It is 44 characters. It says discount. The flag is fatal. The context is an invoice line or a credit note line. The published test counts cac:Price/cac:AllowanceCharge/cbc:Amount. The count comparison has a space before <= and a space after it.

## What to change

On an invoice line or a credit note line, send at most one item price discount.

## Illustration

Illustration of the condition in the official statement. Not an example published by the source.

**Fails the stated condition.** An invoice line has two item price discounts.

**Passes the stated condition.** An invoice line has one item price discount, or none.

## Published context and test

Copied from the source. Not reimplemented on this page.

```
cac:InvoiceLine | cac:CreditNoteLine
```

```
(count(cac:Price/cac:AllowanceCharge/cbc:Amount) <= 1)
```

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