CII-SR-256: Leave out the ID of the buyer's contact

What it means

The buyer's contact (BG-9) must not have an ID element, which would hold a reference number for the contact. The standard carries only a contact point (BT-56), a telephone number (BT-57) and an email address (BT-58). The same restriction applies in the CII rules for XRechnung, NLCIUS and the French CTC rules.

Why it matters

This is a warning, so the file is still accepted. The recipient's software does not read a contact ID, so it is ignored. If the number is meant to help the buyer route the invoice, the buyer reference (BT-10) is the field for that, and it only works there.

How to fix it

Open the contact person on the customer record and clear any contact number or contact ID that your software exports. If the number should reach the buyer's team, enter it as the buyer reference instead. If you edit the XML yourself, delete the ID element inside the buyer's DefinedTradeContact.

The rule as published

ID should not be present

Where this rule applies