Early Lease Termination

[Jon S.]

Tenant bought a house and terminated his 9 month rental lease 4 months early.  There is no early termination clause in the lease, the tenant is on the hook for the entire lease, but I am fine with an early termination fee of  2 month rent penalty. The questions are 1) Can I charge 2 months rent penalty for early termination? 2)  What form do I use to inform the tenant that I am charging 2 months rent as early termination fee? 3) How much time do I have to inform tenant? 4) Since he paid first, last and security, I intended to use "Notice of Intent to Impose Claim on Security Deposit" for the entire 2 months rent, but wondered whether or not the last months rent can be considered a security deposit and treated the same as a security deposit, or must it be treated differently? I thought that since it is a last months rent deposit, I could use it to pay the April rent, and only write the "Notice of Intent to Impose Claim on Security Deposit" for withholding the security deposit. I'm just not sure what is the right way to do this. Maybe both ways are acceptable, but I want to make sure I do it correctly and legally. Thank you

Background: There was some discussion about the possibility that they might buy a house, and they asked what would be the penalty, to which I responded that I didn't know, but we also discussed that the usual and customary seems to be 2 months rent penalty, and they concurred that was the typical solution, so we left that conversation unsettled but in agreement that 2 months rent penalty would seem to be fair. The signed lease was issued after this discussion and contains no early termination clause, and tenant signed lease without any such clause. The lease also contains a 60 days notice clause if tenant is ending the lease, but tenant provided less than 60 days notice, they provided 27 days notice to be exact. Otherwise, tenant was a good tenant, we had no problems during their entire stay. Note: Tenant owes a little more than the 2 months rent penalty which I have in deposits, due to a utility bill and a mandatory cleaning fee, so tenant will actually owe a little more than what I have in deposits, less than $200 more, so I will have to request payment from them for the additional amount due.  

How do I do this correctly? Thank you