Keep in mind that mortgage lenders only take account of three years of payment history to refinance your mortgage loan. ...Refinancing a mortgage loan can lower interest rates of your existing bad credit home loan. To ensure that you will be getting the best mortgage rate, find out if the lending company you are dealing with has a broker. This is fundamental if you want to get the best mortgage rates and save your money. Contracting a broker may mean additional fees to subtract from your budget.