CII-SR-422: Leave out LineID in the preceding invoice reference

What it means

The reference to a preceding invoice (InvoiceReferencedDocument) must not contain a LineID, which points to one line of that earlier invoice. EN 16931 lets you refer to the earlier invoice by its number (BT-25) and date (BT-26), but not to a line on it.

Why it matters

This rule is a warning, so the file is still accepted. The reference to the earlier invoice is fine; only the pointer to a line is outside the standard, so the recipient's software is not expected to read it.

How to fix it

Delete the LineID from the preceding invoice reference and keep the invoice number and date. If it matters which line is meant, say so in an invoice note (BT-22). This reference is mostly used on credit notes and corrections, so check the export settings of your software if it adds the line each time.

The rule as published

LineID should not be present

Where this rule applies