Two things are certain about almost every landlord-tenant relationship: that the tenant will be required to deposit money with the landlord as security before moving in; and that the relationship will end at some point. So what happens to the security deposit? Generally, the landlord has a duty to return it to the tenant when he or she moves out. But not surprisingly, sometimes the tenant causes damages to the apartment. In those cases, the landlord will want to assert a claim to the security deposit to setoff the cost of repairing the damages. You may be surprised to learn that depending on how a landlord handles the security deposit, he or she may have no claim to it at all, and may have to return it in full to the tenant.