Yes, a client may connect one portal login/username with many accounts. To do so, they must login into their account and then go to the Account List tab. Here, they can select Add An Account to add additional accounts. From here they can also switch accounts within the same login. When a client has many accounts connected to one login, keep the following in mind: 

• Each login can only be associated with one type of client. This means that an owner login cannot connect to a tenant account, and vice versa. However, an owner login can be connected to an unlimited number of owner accounts. 
• Any notification emails will go to the email address(es) in their profile, not the email address they are logging in with. 
• The accounts a client connects to can be from more than one property manager. This is not uncommon among owners with large portfolios who use different property managers depending on the type of property. 
• If you view a client's portal through your account, you will only view the portal for that particular client ID. If the client has other accounts connected to their portal, you will not be able to see this. This is a safety precaution to protect clients' information when they are doing business with multiple property managers. 

In the inverse of this, a single managed account can have many different email addresses (portal logins) that connect to it. This is common in situations where a husband and wife have separate email addresses that they want to use to access their family's managed account, or when numerous members of a corporation or trust want to access a single managed account with different email addresses. You could even have a scenario where husband and wife each access the family account with their respective email addresses, but the husband's login is also connected to his brother's managed account, while the wife's is not.