UBL-CR-588: Additional item identifiers are not used on invoice lines

What it means

The rule looks at the item on every invoice line (or credit note line) in a UBL file. It warns when the item contains a cac:AdditionalItemIdentification block. EN 16931 has three item identifiers: the seller's (BT-155), the buyer's (BT-156) and the standard one (BT-157). This warning applies whenever cac:AdditionalItemIdentification is present, even if those other identifiers are absent.

Why it matters

EN 16931 does not use additional item identification blocks on invoice or credit note lines.

How to fix it

Decide what the extra number is. Your own article number goes in the seller's item identifier, the buyer's article number goes in the buyer's item identifier, and a GTIN or similar code goes in the standard identifier with its scheme. A code that groups items belongs in the item classification identifier (BT-158). In the XML, move the value first if it belongs in one of those fields, then delete cac:AdditionalItemIdentification from cac:InvoiceLine/cac:Item (cac:CreditNoteLine in a credit note).

The rule as published

A UBL invoice should not include the InvoiceLine Item AdditionalItemIdentification

Where this rule applies