Multiple instance of Zoho

I have c. 25 clients for whom we engage in telemarketing campaign for. Each client currently has an instance of Highrise and adds the account manager at my firm using the email address of the clients agency as a user so they can undertake the activity in that account. With Highrise, if they also add me as a user, using my own RSW email address, Highrise recognises that the same email address is associated with multiple instances, so I can simply flick from one to another on any one dashboard. Does Zoho do something similar?