Target ID for reference is necessary for only seeing invoices of arrownet and JPX Co-location. It is different from the ID you already have to refer report and notice.

To change the registration information (Name, Telephone number, E-mail) of Target ID for invoice, after logging in to Target (for invoices), edit the target user ID registration information from "ユーザ基本情報設定" > "ユーザ更新" link button in the screen header.