Cohabitation can work out really well for those couples who are serious about each other but not quite ready for marriage. It can extricate them from roommate situations while easing the financial burden of living alone. But living together can create financial issues among couples, who may be unsure whether a joint bank account is a good idea. A recent study found that couples who keep finances separate are no happier than those who pool their resources. There are pros and cons to keeping finances separate, but regardless of the decision, couples must have similar financial goals in order for things to work out. Consider some of the following financial challenges. If you've just gotten out of splitting household expenses with a roommate, then moving in with your significant other and doing the same can feel less than romantic. Writing your boyfriend a check for half the rent, for example, can seem a little strange. Not having insight into the other person's expenses can be a major disadvantage to couples who intend to marry because it's helpful to know his or her spending habits before committing to financial obligations jointly down the road, such as taking out a mortgage or saving for retirement.