While the simpler option is to stay with your existing lender, it might not be profitable for you to do so. Therefore, it is still worth switching to a new lender, even though you will have to go through the application process again and have a new credit check carried out on you by the new mortgage provider. Despite this hassle, making the switch is easier than you think, especially if you use a mortgage broker, as they will find you a new deal, liaise with your lender, and help you with every aspect of the mortgage application.