For years, paying off credit cards and loans has been the main way to build credit. With Experian's purchase of RentBureau, a credit bureau for multifamily housing, paying apartment rent will count, too. The object is to help, so only positive histories count. But if you already have lots of debt, listing rent could raise a red flag. Lease obligations are looked at in the same way as an installment loan -- $1,000 a month for a year is regarded as a $12,000 debt. The information will be part of your VantageScore, from Experian, but not the more common FICO score.