Support by service : Frequently Asked Questions about NTT DOCOMO BUSINESS Business Portal
Service menu support information
How can I change "User Name" and "Contact (Phone#)"?
You can change login ID (email address) using "Edit Profile" menu, access from your user name located in header.
In the Edit User Profile screen, Change "User Name" and "Contact (Phone#)" then "Save" button.
In the Edit User Profile screen, Change "User Name" and "Contact (Phone#)" then "Save" button.