Should newly added Tenants Pay additional Deposits?

[Val J.]

Happy New Year!  I need help with something I'm about to do present to my current  tenant.  I have done my research and have learned that the tenant has unauthorized people living in the property. I plan to meet with the tenant Friday to discuss this and to offer a 2 possible solutions.  Solution A.  The individuals not on the lease will have to be properly vetted just as the original tenant was.  If tenant is not in agreement with this,  I will present her with a 30 day notice for ALL to vacate.  Solution B. If the tenant does agree and wants all to remain, I will ask for a non-refundable application fee from each person. I do background checks via Smartmove so each individual would pay for this and have to qualify separately. 

Now here's where I need help. The tenant has of course already paid a deposit upon move in 2 years ago. Since then rent has increased. Should I require a NEW deposit from each individual? I'm thinking this deposit would be equivalent to the current rent rate.  Or should I required a deposit amount equal to what the original tenant paid? I was thinking that if new people qualify I  would inform them via a new lease agreement signed by all that the deposits they provide would not be returned by me until ALL have vacated the property. If there's a parting of ways these individuals would have to work out their disagreements among themselves and whomever remains would have to provide a deposit refund to the person(s) who vacate.