Be sure to manage permissions for the team member - 

And select to Invite.

Note that, Form access can be restricted BUT not client details access.

Details access can only be controlled by setting up separate instances of LodgeiT , using Switch Organisation

Form access can be managed by Settings -->Form Access

1. Select client to work on -

2. Select "Settings" and click "Form Access"

Related article: How to Lock a Form from the other Team