What a lock is
A rate lock freezes your interest rate for a set window - usually 30, 45, or 60 days - while your loan closes. Without one, your rate floats with the market until shortly before closing. The lock is a commitment on both sides: the lender honors the rate even if the market rises.
When to lock
Lock when you are under contract and comfortable with today math. Trying to time the bottom of a rate cycle with your family home is speculation with your housing costs. If the payment works today, the smart move is usually to take the certainty.
Float-downs and extensions
Some locks include a float-down: if rates drop meaningfully before closing, you get one chance to re-set lower, typically for a fee or a slightly higher starting rate. Extensions cost money per day - another reason fast document turnaround protects your wallet.
After you close
A lock is not a life sentence. If rates fall substantially after you buy, refinancing captures the improvement - and we monitor closed clients rates and call when the math clears their break-even. That call is free; you just have to be our client to get it.