When should you lock your mortgage rate?
In this article
Lock your mortgage rate once you have a signed contract, a closing date your lock can cover, and a payment you are comfortable with. The Consumer Financial Protection Bureau (CFPB) says rate locks are typically available for 30, 45, or 60 days, and sometimes longer. If you are buying a new home that is still being built, the timing is trickier, so ask your lender early how long a lock you need and what it costs.
What is a mortgage rate lock?
A rate lock means your interest rate will not change between the offer and closing. That is how the CFPB explains it (page checked Sept. 27, 2026). There are two conditions: you must close within the time frame, and there can be no changes to your application.
Without a lock, the CFPB says your rate "can change at any time." Mortgage rates can move daily, sometimes hourly.
A locked rate can still change if your application changes. The CFPB lists common reasons:
You change the kind of loan or the size of your down payment.
The appraisal comes in higher or lower than expected.
Your credit score changes, for example because you took out a new loan or missed a payment.
Your lender cannot document overtime, bonus or other income.
So once you lock, keep your finances steady until closing. Avoid new credit and big changes.
How long does a mortgage rate lock last?
The CFPB says rate locks are typically available for 30, 45 or 60 days, and sometimes longer. Policies vary by lender.
You can see whether your rate is locked at the top of page 1 of your Loan Estimate. The Loan Estimate is a three-page form, and the CFPB says your lender must give it to you within three business days of receiving your application. Some lenders lock your rate when they issue the Loan Estimate, and some do not.
If your rate is locked for a set period, Regulation Z section 1026.37(a)(13) says the Loan Estimate must show the date and time, including the time zone, when that lock period ends. Put that date on your calendar.
Why does lock timing matter right now?
Rates have moved fast this year. Here is what Freddie Mac's weekly history file shows for the 30-year fixed average:
EXAMPLE ONLY: $400,000 loan, 30-year fixed. Principal and interest only. Taxes and insurance not included. Rates are Freddie Mac weekly averages, not a quote for your loan.
Week (Freddie Mac average) | 30-year fixed rate | Monthly principal and interest |
|---|---|---|
Feb. 26, 2026 | 5.98% | $2,393.06 |
Aug. 27, 2026 | 6.66% | $2,570.51 |
Sept. 24, 2026 | 7.03% | $2,669.27 |
In just four weeks, from Aug. 27 to Sept. 24, 2026, the average rose from 6.66% to 7.03%. On this example loan, that adds about $99 a month. The latest Freddie Mac survey shows the 7.03% average as of Sept. 24, 2026, up from 6.95% the week before.
That is the risk a lock protects you from. But there is a flip side. The CFPB warns that a lock "may lock you out of a lower interest rate if rates fall after you get your loan offer." Nobody can promise which way rates will go next.
When should you lock your mortgage rate?
There is no perfect day. But these signs usually mean you are ready to talk to your lender about locking:
You have a signed purchase contract and a realistic closing date.
Your lock period can cover that closing date. The CFPB says to make sure your rate lock agreement is long enough to cover the time until you close.
You have a Loan Estimate you understand, and the payment at that rate fits your budget.
Your finances are settled. No new credit, no job change and a down payment amount you will not change.
If you are worried your lock is too short, the CFPB suggests asking your lender about switching to a longer lock period now, not later.
What does a rate lock cost?
It depends on the lender. The CFPB says a lock "may be expensive to extend" if your purchase needs more time. Its Loan Estimate guide also lists rate-lock fees as one kind of origination charge some lenders include.
Here is the catch. The CFPB says your Loan Estimate will show whether your rate is locked, but it will not show how much it would cost to extend the lock, how much you are paying for your lock period, or whether a different lock period would cost more or less. You have to ask.
The CFPB suggests these questions:
"What does it mean if I lock my rate today?"
"What rate lock time frame does this Loan Estimate provide?"
"Is a shorter or longer rate lock available, and at what cost?"
"What if my closing is delayed and the rate lock expires?"
"If I lock my rate, and interest rates go down, what happens?"
Ask every lender the same questions, and compare the answers in writing.
What happens after you lock?
If your rate was not locked when you got your first Loan Estimate, Regulation Z section 1026.19(e)(3)(iv)(D) says the lender must give you a revised Loan Estimate no later than three business days after the rate is locked. (If you lock after you already have your Closing Disclosure, the rules call for a corrected Closing Disclosure instead.) The revised Loan Estimate will show the locked rate, any points and any lender credits. Check it against your first Loan Estimate line by line.
What this means for new-construction buyers
Buying a home that is not built yet changes the math. A standard 30-, 45- or 60-day lock can be much shorter than a build.
The Census Bureau's Survey of Construction tracks how long builds take. For single-family homes built for sale, its start-to-completion table shows an average of 6.1 months in 2025. Its authorization-to-start table shows an average of 1.4 months from permit to the start of construction for the same type of home in 2025. Your builder's schedule may be shorter or longer.
Timeline | Length | Source |
|---|---|---|
Typical rate lock | 30, 45 or 60 days, sometimes longer | CFPB |
Permit to start of construction | 1.4 months average (2025) | Census Bureau |
Start to completion | 6.1 months average (2025) | Census Bureau |
The federal rules also have a special section for new construction. Under Regulation Z section 1026.19(e)(3)(iv)(F), when the lender reasonably expects closing more than 60 days after your Loan Estimate, it may issue a revised Loan Estimate, but only if your original Loan Estimate clearly says it may do so any time before 60 days before closing. Look for that statement on your Loan Estimate and ask your lender what it means for you.
Before you lock on a new home, ask:
What is the builder's estimated completion date, and how firm is it?
Does the lender offer a lock long enough for my build, and what does it cost?
What is the cost to extend if construction runs late?
Is the builder offering any help with the rate or closing costs? Offers change often, so call 561-704-0091 for today's numbers.
A lock and a buydown are different tools. A lock holds your rate until closing. A buydown lowers your payment after closing. Our 2-1 buydown guide explains how that one works.
National House Search is builder-neutral. We can help you compare build timelines and offers across builders before you pick a home.
Common Questions
How long does a mortgage rate lock last?
The CFPB says rate locks are typically available for 30, 45 or 60 days, and sometimes longer. Lock policies vary by lender. Ask what lock periods your lender offers and what each one costs.
What happens if my rate lock expires before closing?
The CFPB says a rate lock may be expensive to extend if your purchase needs more time. Ask your lender before you lock what happens if closing is delayed and what an extension costs. Get the answer in writing.
Can my rate change after I lock?
Yes, if your application changes. The CFPB lists changes to your loan type or down payment, an appraisal that comes in higher or lower, a change in your credit score, or income your lender cannot document.
Does my Loan Estimate show my rate lock?
Yes. The CFPB says to check the top of page 1 of your Loan Estimate to see if your rate is locked and for how long. It will not show what an extension costs, so ask your lender.
Should I lock my rate when I sign a contract on a new home?
It depends on your completion date. The Census Bureau's 2025 data shows single-family homes built for sale took an average of 6.1 months from start to completion, which is longer than a typical 30- to 60-day lock. Ask your lender how long a lock you need and what it costs.
What if rates go down after I lock?
The CFPB warns that a lock may keep you from getting a lower rate if rates fall after your loan offer. It suggests asking your lender what happens in that case before you lock.
Ready to take the next step?
Call 561-704-0091 to talk with a National House Search specialist, or Schedule a visit.
Related reading: What is a 2-1 buydown and is it worth it? · Buying a new-construction townhome for the first time · Condo vs. townhouse vs. single-family home
This is general information, not financial, tax or legal advice. Figures checked September 27, 2026.