It is the job of mortgage company Plymouth MN to find good interest rates and lock it in for you. They are also responsible for closing the deal on a house in time. Once a house is bid for, there is usually a time frame within which the deal needs to be closed. A lender charges a bunch of different fees, like closing fees and administrative fees for instance. Because these are determined by him, it is also is his hands to do away with any of them, which can save you a lot of money.