One Tenant Leaves, While Tenant wants to remain

[Nathan Moore]

Recently, I've had a tenant (one of three) contact me that he will be vacating the our rental for another place with his girlfriend. The tenant just signed a lease extension, which will begin in a 15 days. 

This is the second time I've had roommate issues effect the term of a lease & am finding that leasing to roommates can be complicated.  Typically, I wouldn't mind tenants moving out if the tenants that are remaining are great tenants without any problems and can afford the rent.

My major concern is that when we accepted these tenants, we accepted them based upon their combined income (3x income/rent ratio).  Now, due to a tenant leaving, they no longer meet the rental requirements (even if they say they can pay the rent).  I was wondering what our rights are with the remaining tenants?  From my understanding, we would just keep the lease as-is & the tenant that is leaving is held liable in case of default. 

In addition, I was wondering what you do in order to discourage co-tenants from leaving in the middle of the lease.  Do you have clauses with fees for one tenant to leave as well as requirements to find a new tenant?  Can you consider one tenant leaving as breaking the lease?

Appreciate your thoughts & help.