If you are able to get a lower rate that what you currently have, you can save tens of thousands of dollars over the life of your loan. Also, most lenders don't charge as many fees to refinance a mortgage and depending on how much equity you have in your home you may be able to roll the closing costs into your new loan, still have a lower balance than your original loan, a lower rate, and a lower payment.
Close inactive credit card accounts to improve your credit score, making you eligible for lower interest rate loans. You will need to notify the credit card companies in writing that you wish the accounts closed on your request. Next, check your credit report after 30 days to be sure closed accounts include the comment "Closed at Customer's Request." You want future lenders to know it was your request and not bad credit that closed your accounts. Also, take the time to check for any mistakes in your credit report that could negatively impact your credit score.
Before you refinance a loan, make sure that you carefully analyze any fees that your lender is including on the loan. The Department of Housing and Urban Development can provide you with a list of standard fees. Use it to make sure that your lender isn't tacking on anything extravagant. And by all means, compare their fees with other lenders in the market.
If there is a big difference between the initial interest rate and the APR listed in the ad, it may mean that there are high fees associated with the loan.