When two or more people sign the same rental agreement or lease—or enter into the same oral rental agreement—they are cotenants. That means they share the same legal rights and responsibilities. This legal principle, known as “joint and several liability,” has enormous implications for cotenants.
There's an important distinction to be made here: We are talking about housemates who are cotenants, not tenant and subtenant. A tenant and subtenant (for example, someone who has sublet an apartment from you and has not signed the lease or rental agreement) do not share the same rights and responsibilities with respect to each other or to the landlord. See Legal Issues With Roommates for the legal definitions.
Joint and several liability is the legal version of the slogan of the Three Musketeers: “One for all and all for one.” Here’s what it means to tenants:
It’s that simple, unfair as it can seem at times.
How can you avoid taking the fall for your roommate’s screw-ups? The best answer, of course, is to choose your housemates carefully.
Even solid friendships will benefit from thinking ahead to possible areas of friction and planning ways to avoid problems. To be blunt: When it comes to paying rent and making good on damage, you are your cotenant's guarantor—if he or she doesn't come through, you pay.
But joint liability doesn't mean that you can evict a cotenant. Only landlords can do this. See the Roommates section of Nolo for more on the subject.
This means that cotenants cannot force each other out. If your roommate becomes insufferable, you’ll have to work it out between the two of you unless the roommate’s behavior is also a violation of a lease or rental agreement clause (for example, illegal drug use). Although a violation of this nature would justify the termination of both your tenancies (joint and several liability!), you might get lucky if your landlord pities you and lets you stay.
Roommates make lots of informal agreements about splitting rent, sharing chores, and choosing bedrooms. It’s important to understand that such agreements do not affect the joint and several liability of cotenants to the landlord. Just because you and your cotenants agreed to share cleaning and maintenance duties doesn’t change the fact that each one of you is liable for any damage done to the apartment.
And just as your landlord isn’t bound by any agreements between roommates, your landlord cannot enforce them, either. If one roommate breaks an agreement made with the rest of the cotenants to pay one-third the rent, don’t bother asking your landlord to force the roommate to pay up.
Since the arrangements between you and your roommates will have a huge effect on your day-to-day life, you should take them seriously. Before you move in, sit down with your roommates and discuss the major issues that are likely to come up, then draft a Roommate Agreement for all of you to sign. Even though your enforcement options are limited, being able to point to a roommate's signature on the agreement can bolster your argument in a dispute.