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Rates & Market

Mortgage Rate Lock Explained: When to Lock, How Long and What It Costs

Locking your mortgage rate is like calling "dibs" on a price while the market keeps moving. Here is how rate locks work, how long to lock and the sneaky things that can still change your rate.

By Keys & Coffee Editorial Team · Updated · 6 min read

Hourglass sitting on a wooden table
Quick answers

  • What it is: a rate lock is a lender’s promise to hold a specific interest rate (and points) for a set period while your loan is processed.
  • How long: locks commonly last 30, 45 or 60 days, and sometimes longer.
  • The catch: you must close before the lock expires, and your application must not change in ways that affect pricing.
  • Where to see it: the top of page 1 of your Loan Estimate shows whether your rate is locked and until when.
  • Get it in writing: ask for written confirmation of the rate, points and expiration date.

Mortgage rates move every day, sometimes more than once. A rate lock is how you call “dibs” on today’s rate while the paperwork, appraisal and underwriting catch up.

It sounds simple, and mostly it is. But the details, like how long to lock and what can still change your rate, are where people get surprised. Let’s clear them up.

How a rate lock works

When you lock, the lender agrees to give you a specific rate with a specific number of points, as long as you close by a certain date. If rates rise during that time, your rate stays put. If rates fall, your rate also stays put, unless you have a float-down option (more on that soon).

According to the CFPB, the lock holds as long as you close within the time frame and there are no changes to your application. That second part is important.

Myth buster“Once I lock, nothing can change my rate.” Not quite. The CFPB notes that a locked rate can change if you change the loan type or down payment, the appraisal comes in different than expected, your credit score changes, or the lender cannot verify parts of your income.

What can still change a locked rate

  • Changing the loan. Switching from a 30-year to a 15-year, or from FHA to conventional, changes the pricing.
  • A different down payment. Putting less down can change your loan-to-value and your rate.
  • The appraisal. If the home appraises higher or lower than expected, your loan-to-value moves.
  • Your credit. A new car loan or a missed payment during the process can lower your score. This is not the time to finance a new sofa.
  • Income documentation. If overtime or bonus income cannot be documented, the loan may need to be re-priced.
  • Running out of time. If the lock expires before closing, you may have to pay to extend it or re-lock at current rates.

How long should you lock?

Long enough to close comfortably, but not so long that you pay for time you do not need. Longer locks often come with a slightly higher rate or fee, because the lender is taking on more risk.

Lock length Often a fit when…
30 days You have a signed contract and a straightforward file
45 days Typical purchase timeline with a little cushion
60 days Closing is further out, or the file is more complex
Longer locks New construction or unusual timelines; ask about cost

Ask your lender what a realistic closing timeline looks like for your situation, then add a buffer. Appraisals and title work do not always run on schedule.

When should you lock?

Nobody can reliably predict where rates are headed next week, and anyone who says otherwise is guessing with confidence. A more useful question: what payment can you live with?

  • If today’s rate gives you a payment that fits your budget, locking removes the stress of watching rates every morning.
  • Many lenders lock only once you have a signed purchase contract and a property address.
  • Some lenders lock when they issue the Loan Estimate, others do not. Check page 1 to see which you have.

For a sense of the recent rate environment, our October 2026 mortgage rates update gives the bigger picture.

Example

You are borrowing $350,000 on a 30-year fixed loan. You lock at a hypothetical 6.25%, and during the next month rates rise to 6.75%.

  • At 6.25%, principal and interest are about $2,155 a month.
  • At 6.75%, they would be about $2,270 a month.
  • The lock saves you about $115 a month, which is roughly $41,400 over 30 years if you kept the loan that long.

Now say your closing slips and the lender charges a hypothetical 0.125% of the loan to extend the lock: that is $350,000 x 0.125% = $437.50. Annoying, but much cheaper than re-locking at a higher rate. Rates and fees here are illustrative only.

Try different rates in our mortgage calculator to see what a quarter-point really means for you.

Rate lock fees and extensions

Lock policies vary a lot by lender. Some include the lock at no extra charge for standard periods. Others charge an upfront fee, or price longer locks with a higher rate. The CFPB points out that your Loan Estimate does not show the cost of extending your lock, so ask directly:

  1. Is there a fee to lock? Is it refundable?
  2. How much does an extension cost, and how long can I extend?
  3. What happens if the lock expires because of a delay on the lender’s side?
  4. Do you offer a float-down, and what does it cost?

What is a float-down?

A float-down option lets you take a lower rate if market rates drop after you lock. Not every lender offers one. Those that do often charge a fee or require rates to fall by a minimum amount. It can be worth it in a volatile market, but read the fine print before you pay for it.

Fun factA rate lock usually covers more than just the rate. It also locks the pricing, meaning the points or lender credits tied to that rate. That is why “Is my rate locked?” and “Are my points locked?” should get the same answer. Our guide to mortgage points explains how they trade off.

Rate locks when refinancing

Locks work the same way for refinances. Timelines can be shorter because there is no purchase contract, but appraisals and title work still take time. If you are weighing a refinance, see our guide on when to refinance and run the numbers in the refinance calculator.

Your rate lock checklist

  • Get the lock in writing: rate, points, lock date and expiration date.
  • Confirm the lock on page 1 of your Loan Estimate.
  • Respond quickly to every document request from your lender.
  • Do not open new credit or make big purchases until after closing.
  • Check in with your lender a week or two before the lock expires.

FAQ

Does locking my rate cost money?

It depends on the lender. Standard locks are often included in the pricing, but longer locks and extensions may cost extra. Ask before you lock.

Can I switch lenders after locking?

Usually yes, but you may lose any lock fee you paid, and you will have to lock again with the new lender at their current rates.

What happens if my lock expires?

You may be able to pay for an extension, or you may need to re-lock at current market rates, which could be higher or lower.

Can I lock before I find a house?

Most lenders lock only once you have a property and a purchase contract, though some offer special programs. Ask your lender.

Should I wait for rates to drop before locking?

That is a gamble. Rates can move either way. Locking when the payment fits your budget takes the guesswork out.

Keys & Coffee is an independent education site and is not a lender. Examples are for illustration only. Sources: Consumer Financial Protection Bureau (rate locks and the Loan Estimate), Federal Reserve Board consumer guidance on mortgage lock-ins.

Keys & Coffee Editorial Team

We turn lender-speak into plain English. We check our numbers against official sources like the CFPB, HUD, Fannie Mae and Freddie Mac, and we update guides when the rules change.

Keys & Coffee is an independent education site. We are not a lender or mortgage broker, we do not take loan applications or payments, and nothing here is financial advice. This site is not affiliated with Axia Home Loans, Axia Financial, LLC, or Planet Home Lending. Rates and rules change often — always confirm details with a licensed loan officer and check any lender on the NMLS Consumer Access site.

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