# UBL-SR-26

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

> Payment reference shall occur maximum once

Source: https://docs.peppol.eu/poacc/billing/3.0/rules/ubl-tc434/UBL-SR-26/

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 payment reference shall occur at most once. The statement has no period and says shall. It is 42 characters. The flag is fatal. The context is cac:PaymentMeans. The published test counts cbc:PaymentID. The comparison has a space before <= and a space after it.

## What to change

Send at most one payment identifier on the payment means.

## Illustration

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

**Fails the stated condition.** The payment means has two payment identifiers.

**Passes the stated condition.** The payment means has one payment identifier, or none.

## Published context and test

Copied from the source. Not reimplemented on this page.

```
cac:PaymentMeans
```

```
(count(cbc:PaymentID) <= 1)
```

[All rule notes](https://einvoicegoblin.com/rules/index.md) · [JSON](https://einvoicegoblin.com/rules/UBL-SR-26.json) · [HTML](https://einvoicegoblin.com/rules/UBL-SR-26/) · [llms.txt](https://einvoicegoblin.com/llms.txt) · [Invoice page](https://einvoicegoblin.com/) · [Privacy](https://einvoicegoblin.com/privacy.html)