It can be beneficial to refinance your mortgage when rates drop, as it could result in lower monthly payments and potentially significant savings over the life of your loan. However, there are costs associated with refinancing, such as arrangement fees for the new mortgage and potential early repayment charges on your existing mortgage. These costs need to be weighed against the potential savings from a lower rate. A mortgage broker or financial advisor can help you make these calculations and decide whether refinancing is a good option for you.