Whenever someone chooses to rent an apartment or home with another person (presumably not a spouse for our purposes), there is some inherent risk involved. Under the best of circumstances, each of you will remain in the apartment until the lease term is up and you both vacate without issue. An individual, however, can never count on the best case scenario playing out and should plan for the worst.

When individuals sign a lease and rent a dwelling together, the law considers them co-tenants to the landlord. Under the terms of the lease, those individuals not only make certain representations to their landlord, but they become legally obligated to him pursuant to the terms of that lease. Under most circumstances, co-tenants assume joint and several liability for one another’s actions. In the simplest of terms, this means that an innocent tenant can be made to suffer the consequences of another tenant’s misdeeds. A simple example of joint and several liability arises under circumstances where your landlord holds you responsible for your roommates failure to remit his portion of the rent.

Seem unfair? Well, maybe it is, but that’s what you signed on for when you took on a roommate. The question is what can you do about it? You might be thinking that whatever arrangement you made with the co-tenant will absolve you of your alleged sins with the landlord, but you would be absolutely wrong. Whatever arrangement you might have with your roommate regarding rent or other responsibilities will be utterly immaterial to the landlord (after all, he wasn’t a party to that agreement and really is only concerned with getting paid). You, therefore, need to try and protect yourself in another way.

The answer to this dilemma is twofold, although I offer this caveat: neither solution will protect you against liability toward the landlord should something go wrong; these solutions are meant only to minimize the likelihood of something going wrong and thereafter providing you with some measure of recourse.

The first bit of advice I would offer is choose your roommates wisely! If you’re taking on a roommate cold or without any real knowledge of potential candidates, be thorough in your interview process. Not only should you make sure that they will be a good fit for you and your lifestyle (opposites aren’t always a good thing after all), you should try to ensure both their financial stability and their previous rental history. If someone’s been a flake in the past, she’s probably not going to be a great risk this time around either. The same holds true for friends that you’re considering taking on as co-tenants. Trite as it might sound, even close friendships can benefit from looking to potential pitfalls down the road and trying to avoid them.

That leads us to my second recommendation: Co-tenants should almost always consider utilizing a Roommate Agreement. While co-tenants routinely make informal agreements about relative responsibilities, it’s a good idea to boil those responsibilities down to writing. The agreement isn’t complicated and it might just protect your interests later on when and if something does go wrong. The agreement should set forth the roommates’ respective responsibilities for, but not limited, to: everyone’s share of the rent; which bedrooms each party will occupy; responsibilities for household chores and the schedules for same; shopping and cooking responsibilities; permissibility of overnight guests; and, finally, what happens if one tenant wants to move out early.

While it might seem overkill and totally unnecessary, especially among friends, a simple agreement setting forth your relationship and these responsibilities with your roommates can be a invaluable tool when issues do arise. This will be especially true if your co-tenant ever leaves you holding the proverbial bag with your landlord for damages or unpaid rent. Although the landlord can enforce the lease terms against you, that roommate agreement you thought so unnecessary early on could make a world of difference if you ever want to commence an action to recover the money you ended up paying the landlord because of your now ex-roommate.