Mortgage rates can move day to day — sometimes hour to hour. A rate lock is your lender’s promise to hold a specific interest rate for you for a set window of time, so a jump in the market between your offer and your closing doesn’t raise your monthly payment. For a first-time buyer, understanding when and how to lock can save real money and a lot of stress.
How a rate lock works
When you lock, your lender guarantees a particular interest rate (and often the associated points and fees) for a defined period, typically 30, 45, or 60 days. As long as you close within that window and nothing major changes about your application, that’s the rate you get — even if market rates rise in the meantime.
The tradeoff cuts both ways. If rates fall after you lock, you’re generally still committed to the locked rate unless your lock includes a “float-down” option (more on that below). A lock protects you from increases; it doesn’t automatically capture decreases.
When can you lock?
You typically can’t lock a rate until you have a property under contract and an active loan application. Some lenders let you lock right after your offer is accepted; others prefer to wait until later in processing. Once you lock, the clock starts, so you want your lock period to comfortably cover the time it takes to close — which for first-time buyers often runs 30 to 45 days.
Talk to your loan officer about realistic timelines. If your closing is 40 days out, a 30-day lock is risky; a 45-day lock gives you breathing room.
Lock periods and cost
Shorter locks are usually cheaper (or free) and longer locks cost more, because the lender is taking on more risk the longer they guarantee your rate. A 30-day lock might carry no explicit fee, while a 60- or 90-day lock could add a fraction of a point to your cost.
If your closing gets delayed and your lock is about to expire, you may need a lock extension, which typically costs a fee based on how many extra days you need. This is why staying on top of your paperwork and responding quickly to your lender matters — delays can literally cost you.
Float-down options
Some lenders offer a float-down provision, which lets you take advantage of a lower rate if the market drops significantly after you lock, while still keeping your protection if rates rise. Float-downs usually cost extra and come with conditions — rates often have to fall by a minimum amount before you can exercise it. If you lock when rates seem volatile or elevated, it’s worth asking whether a float-down makes sense for you.
Locking vs. floating
Choosing not to lock is called “floating” — you’re betting rates will stay flat or fall. Floating can pay off, but it exposes you to increases, and for a first-time buyer stretching to afford a home, the certainty of a lock is often worth more than the chance to save a little by floating. If a small rate increase would push your payment beyond your comfort zone, locking is the safer choice.
Frequently asked questions
How long does a rate lock last?
Most locks run 30, 45, or 60 days, though longer locks are available. You want the lock period to safely cover the time between locking and closing, with a little cushion for delays.
What happens if my rate lock expires before closing?
You’ll usually need to pay for a lock extension, or in some cases re-lock at current market rates. If rates have risen, that can mean a higher payment, so avoiding delays is important.
Can I get a lower rate if the market drops after I lock?
Only if your lock includes a float-down option, which typically costs extra. Without one, you’re generally committed to your locked rate even if the market falls.
Does a rate lock cost money?
Short locks are often free, while longer locks and float-down options usually add to your cost. Extensions to a lock that’s about to expire also carry a fee.