Locking your interest rate means the rate range will stay the same from the time of the rate lock until the rate lock expiration date, regardless of changing market conditions. Even though your interest rate is locked, your final interest rate may be higher or lower than what was initially quoted to you if there are changes before your loan closes. What is a mortgage rate lock? A rate lock is an agreement between you and a mortgage lender. The lender agrees to give you an interest rate with certain fees for a specific time. In return, you agree to accept the lender’s rate and fees and close the loan before the lock expires. Mortgage interest rates are always changing, like stocks, bonds, or any investment. By locking in the rate, the lender guarantees the interest rate on your loan, usually for 30 to 60 days. The guarantee will protect you in the event that rates go up. There is a fee for a rate lock, though you're not likely to see it because it's typically rolled into your interest rate. If rates go down while