When you shop for a mortgage, lenders will review all the information that you submit before giving you a Loan Estimate. Getting a “rate lock” or also called a “lock-in” is one of the decisions you’ll make as you compare Loan Estimates from different lenders. As a first-time homebuyer, it is important that you understand what rate lock means and how it works because it could affect the interest rate you’ll get once you decide which lender you will close a loan with.