Skip to contentNerdwallet icon

Mortgage Rate Lock: When Do I Lock In My Interest Rate?

A mortgage rate lock freezes your interest rate until loan closing to protect your homebuying power from rate hikes.

Bella Angelos
Chris Jennings
Updated
SOME CARD INFO MAY BE OUTDATED

This page includes information about these cards, currently unavailable on NerdWallet. The information has been collected by NerdWallet and has not been provided or reviewed by the card issuer.

Keeping up with mortgage rates can be a challenge. After all, they change every day, and there’s usually no clear indication when they’re about to rise or fall dramatically.
But once you've been approved for a home loan, you can freeze your rate with a mortgage rate lock. In a volatile rate environment, this move could save you thousands of dollars over the course of the loan.
Here's what you need to know about locking in a rate.

Mortgage loans from our partners

NBKC

on NBKC

NBKC

4.5

NerdWallet rating
Min. credit score

620

Min. down payment

3%

New American Funding

on New American Funding

New American Funding

4.0

NerdWallet rating
Min. credit score

N/A

Min. down payment

0%

GO Mortgage

on GO Mortgage

GO Mortgage

4.0

NerdWallet rating
Min. credit score

620

Min. down payment

3%

COMPARE MORE LENDERS
» MORE: Buying a home this year: what’s changed?

What is a mortgage rate lock?

A mortgage rate lock is an offer by a lender to guarantee the interest rate of your loan for a specified period of time. The lender may charge an extra fee or include the cost of the rate lock in the loan. The lock period usually runs from initial approval through closing.
Once locked, the loan’s interest rate won’t change. This remains true no matter what’s happening in the economy, unless your application details change. A rate lock protects you from higher rates, but you won’t get a lower rate, either, unless you have the option for a one-time "float down."
Did you know...
Rate locks can be voided if the information in your application changes. Examples include the property appraisal, your credit score, income or employment, as well as revisions to the loan itself, such as its length or type.

When should you lock a mortgage rate?

Lock in your mortgage rate after you've shopped lenders and are approved for a home loan. Aim for a rate that you feel comfortable with and a monthly payment that fits your long-term budget.
Don't drive yourself crazy by trying to forecast mortgage interest rates, which can be up one day and down the next. Even noted economists can't predict rates with 100% accuracy because events that shape the economy and impact rates are unpredictable.
» MORE: How to get the best mortgage rate

How long can you lock in a mortgage rate?

For standard purchase mortgages, lock periods range from 30 days to 60 days, and sometimes longer. Construction loans have even longer lock periods, such as 12 months. Select one that allows plenty of time to close.
The average time to close a purchase mortgage is 43 days, according to Freddie Mac.
Ask your lender their expected closing timeline, and then consider building in a bit of a cushion to your rate lock period.
» MORE: Closing costs, explained

How to lock in a mortgage rate

Your mortgage lender will probably offer a rate lock after your initial loan application has been approved and before it’s submitted for underwriting, though rate lock policies vary by lender.
Ask about a rate lock if a loan advisor doesn’t mention one. Inquire about available rate lock periods and whether there is a fee.

Mortgage loans from our partners

NBKC

on NBKC

NBKC

4.5

NerdWallet rating
Min. credit score

620

Min. down payment

3%

New American Funding

on New American Funding

New American Funding

4.0

NerdWallet rating
Min. credit score

N/A

Min. down payment

0%

GO Mortgage

on GO Mortgage

GO Mortgage

4.0

NerdWallet rating
Min. credit score

620

Min. down payment

3%

COMPARE MORE LENDERS
» MORE: Best mortgage lenders in a variety of categories

How much does a rate lock cost?

Some lenders charge for a rate lock, though others offer one for free. But like any other "free" service provided by a lender, the fee is baked into the rate you’re offered.
If you do pay for a lock, fees vary widely according to the amount and term of the loan, as well as the length of the lock-in period, and are measured in basis points. For example, a fee of 25 basis points is equal to 0.25% of the loan amount. On a $400,000 mortgage, a 0.25% rate lock fee would be $1,000.

Is a mortgage rate lock worth it?

When rates are going up, a mortgage rate lock is well worth the cost.
Consider a $400,000 home financed for 30 years at 7%, with a 20% down payment. Just a quarter point (0.25%) rise in interest rates will kick your principal-and-interest payments up $54 a month — from $2,129 to $2,183. Over just five years that additional amount will total $3,240.
By comparison, a 0.25% fee to lock in the 7% rate would be $1,000.
Over a six- to eight-week period, from entering into a contract to signing the closing documents, it’s quite possible for rates to move much more than a quarter point.
Worst of all, not locking in a rate can mean having to come up with a higher down payment. If your payment increases because of higher interest rates, a lender may require more money upfront to meet its lending requirements.
» MORE: NerdWallet's picks of best mortgage lenders

How a float-down option works

For an additional fee, a "float down" option lets you snag a currently available lower interest rate. You can usually trigger it only once, and the rate often needs to fall at least 0.25% to activate the option. Including a “float down” in your rate lock agreement is useful in volatile rate environments, potentially saving you thousands of dollars over the life of the loan.
A "float down" option is most often associated with new construction loans and longer-term rate locks, though it never hurts to ask your lender if a "float down" is available for your loan. The terms, parameters and pricing of a "float down" agreement will vary widely among lenders.

Should I lock my mortgage rate today?

Explore today’s mortgage rates for your area and credit score to get a benchmark for your mortgage rate, and ask your loan officer for input about where rates are headed.
Locking in the rate today makes sense if:
  • The rate is affordable and compares well with those offered by other lenders.
  • The rate lock term is long enough to carry you through to closing.
  • Market conditions suggest rates could rise.
  • You want the certainty of a locked mortgage rate.

What happens if my rate lock expires before closing?

If the rate lock expires before closing, your rate will begin to float with daily interest rate movements. To prevent that from happening, talk to your lender before the expiration date to see if the lock can be extended. If you’ve been responding promptly to each information request from the lender, the delays may not be your fault — and you might get a little extra time.

Mortgage loans from our partners

NBKC

on NBKC

NBKC

4.5

NerdWallet rating
Min. credit score

620

Min. down payment

3%

New American Funding

on New American Funding

New American Funding

4.0

NerdWallet rating
Min. credit score

N/A

Min. down payment

0%

GO Mortgage

on GO Mortgage

GO Mortgage

4.0

NerdWallet rating
Min. credit score

620

Min. down payment

3%

COMPARE MORE LENDERS
Explore more on
How to Move in 2026Mortgages
Article sources
NerdWallet writers are subject matter authorities who use primary, trustworthy sources to inform their work, including peer-reviewed studies, government websites, academic research and interviews with industry experts. All content is fact-checked for accuracy, timeliness and relevance. You can learn more about NerdWallet's high standards for journalism by reading our editorial guidelines.
    Back to top

    Looking to buy a home? NerdWallet partners with highly-rated mortgage lenders to find you the best possible rates

    Answer a few questions to match with your personalized offer
    Won't affect your credit score
    Related articles
    Best Mortgage Lenders roundup
    Best Mortgage Lenders
    Georgia Rose's profile picture
    By Georgia Rose
    all-the-types-of-mortgages-explained-in-a-flash
    5 Types of Mortgage Loans for Buyers and Refinancers
    Kate Wood's profile picture
    By Kate Wood
    Tips for First-Time Home Buyers
    Kate Wood's profile picture
    By Kate Wood