Many people and recent graduates need a roommate to make ends meet. After all, what could be better than having someone pay half of your bills? Unfortunately, the realities of sharing the financial responsibilities of running a home can cause friction even among friends. Some people are meticulous in their record keeping and always plan to have enough money available to pay the bill. Others have more difficulty in doing so.

The best way to ensure an equitable relationship is to develop a plan for ensuring fairness in financial aspects of your relationship.

• Divide responsibility for bills equally - A common situation is that one roommate sets up all the utility bills (and even the lease itself) in his or her name alone, and bears all of the financial responsibility. A good plan is to have each roommate take responsibility for one or two of the bills with the goal of having each roommate responsible for the same amount. For example, one roommate could...