BR-64

Explanation

When a standard item identifier (BT-157) is provided — e.g., a GTIN or EAN — it must be qualified by a scheme identifier (ISO 6523 ICD).

How to fix

Add a scheme identifier to the standard item identifier. (Typically a software-side issue, not user input — raise this with your invoicing software vendor; if you're receiving the invoice, ask the sender to address it with theirs.)