A mortgage score is a number that is ascertained through consideration of all the various financial commitments that a person has to pay before being allowed to take out a mortgage. The score must be good for a lender to approve a mortgage and any nonpayment of loans would show up as a negative score. If a person has taken on too much debt compared to their income and repayment possibilities, the mortgage score would indicate that.
Many lenders use this as the definitive decision for whether or not to grant a mortgage to a person. Bad credit stays on a person's record for a set number of years and after it falls off, it is possible for the person to have a better score and proceed to gain credit.