There is a refinancing myth that says you should not refinance your mortgage unless your interest rate will be at least two points less. This myth is not necessarily true if there are other benefits to the refinance or other reasons behind it.
Refinancing a mortgage means the owners are paying off their existing mortgage and replacing that mortgage with a new loan. Generally, the costs associated with mortgage refinancing are rolled into the loan, meaning they are added to the existing balance, increasing the loan amount.
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.
Ask the lender or broker for a comparison of the up-front costs, principal, rate, and payments with and without this rate trade-off.