Some states, however, have roommate laws that allow an additional tenant to move in so long as the original tenant remains in the residence.
Some states also require that a new spouse's name automatically be added to the lease.
In fact, when two or more roommates sign a lease, a landlord can look to each roommate for full payment of the rent, not just his or her share. Moving out doesn't end that obligation. Most often, though, the landlord can only collect the rent owed as it becomes due each month that is remaining on the lease. In some places, however, landlords cannot collect unpaid rent on a broken lease if they haven't made a reasonable effort to find a new tenant. Generally, the landlord must first warn the tenant, usually with a written notice, that a condition of the lease has been violated.