Tenant move out and her mother moved in.

[Ed McIver]

It seems a troublesome tenant has decided to move out. But her mother and mothers boyfriend has moved in. I am reasonably happy to be rid of the original tenant. She always difficult. However, now I have two people who are not on the lease occupying the apartment. 

I feel like I have lost control.

[Nathan Gesner]

Yes, you have lost control. But it's not impossible to regain it!

Serve the mother and her boyfriend notice immediately. If rent is paid for the month of June, I would serve them a notice that they are unauthorized occupants and they are to be out no later than June 30th at midnight. If rent is not paid, I would just start the eviction process.

when you serve notice, is very good chance they will either move out or they will contact you and try to negotiate something. I have policies and procedures, but I am not an unreasonable man and understand the cost of vacancy. I would give them the opportunity to apply, passed my screening, pay a security deposit, and sign a written lease agreement.

The security deposit from the daughter does not belong to the mother and should be treated separately, like you would for any other tenant that abandons a property. This is true even if the mother claims otherwise.