When you're offered a "rate lock" from a lender, it means that you are guaranteed to keep a specific interest rate for a certain number of days while you work on your application process. This ensures that your interest rate can't go up during the application process.
Rate lock periods can be various lengths of time, anywhere from fifteen to sixty days, with the longer ones typically costing more. A lending institution can agree to hold an interest rate and points for a longer period, such as 60 days, but in exchange, the rate (and sometimes points) will be more than that of a rate lock of fewer days.
In addition to opting for a shorter rate lock period, there are other ways you are able to attain the best rate. The larger down payment you make, the smaller your rate will be, as you will have more equity from the beginning. You could opt to pay points to improve your rate over the term of the loan, meaning you pay more up front. One strategy that is a good option for many people is to pay points to reduce the interest rate over the life of the loan. You'll pay more initially, but you'll come out ahead, especially if you keep the loan for a long time.
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