# UBL-SR-17

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

> Buyer legal registration identifier shall occur maximum once

Source: https://docs.peppol.eu/poacc/billing/3.0/rules/ubl-tc434/UBL-SR-17/

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 buyer legal registration identifier shall occur at most once. The statement has no period and says shall. The flag is fatal. The context is the same string as BR-CO-18. The published test counts the buyer legal-entity company identifier. The comparison has a space before <= and a space after it.

## What to change

Send at most one buyer legal registration identifier.

## Illustration

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

**Fails the stated condition.** The buyer has two legal registration identifiers.

**Passes the stated condition.** The buyer has one legal registration identifier, or none.

## Published context and test

Copied from the source. Not reimplemented on this page.

```
/ubl:Invoice | /cn:CreditNote
```

```
(count(cac:AccountingCustomerParty/cac:Party/cac:PartyLegalEntity/cbc:CompanyID) <= 1)
```

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