# UBL-SR-11

> Seller legal registration identifier shall occur maximum once

Checked against Peppol BIS Billing 3.0 2026.5

Canonical: https://einvoicecheck.eu/rules/ubl-sr-11

## Official rule text

Seller legal registration identifier shall occur maximum once

## Why did my invoice fail UBL-SR-11?

The Seller legal registration identifier (BT-30), the company/commercial-register identifier of the seller, may occur at most once. In UBL this is cac:AccountingSupplierParty/cac:Party/cac:PartyLegalEntity/cbc:CompanyID, which must be single-valued.

## Common causes

- Multiple cac:PartyLegalEntity blocks each carry a CompanyID.
- The register number is emitted both with and without a schemeID variant.
- Legal ID and VAT number are both placed in cbc:CompanyID, producing repeats.

## How do I fix it?

```
Keep one company registration ID: <cac:PartyLegalEntity><cbc:RegistrationName>ACME Trading Ltd</cbc:RegistrationName><cbc:CompanyID schemeID="0198">12345678</cbc:CompanyID></cac:PartyLegalEntity> and remove duplicates.
```