# UBL-CR-128

> A UBL invoice should not include the AdditionalDocumentReference Attachment External CharacterSetCode

Checked against Peppol BIS Billing 3.0 2026.5

Canonical: https://einvoicecheck.eu/rules/ubl-cr-128

## Official rule text

A UBL invoice should not include the AdditionalDocumentReference Attachment External CharacterSetCode