Most borrowers treat a rate lock like a light switch: it’s on or it’s off. It isn’t. A lock is a contract with an expiry date printed on it, and the length of that contract directly changes what you pay at closing.
So how long can you lock a mortgage rate? The practical answer for most people is 30 to 60 days. Push past 90 days and you’re into extended-lock territory, where lenders charge real money for the guarantee. Some will go 180 days or even a full year, particularly on new construction, but very few do it for free.
What follows is what those windows actually look like, what the extra days cost, and how to choose one you won’t end up extending at the worst possible moment.
The standard rate lock windows
A 30-day lock is available from essentially every lender. Plenty of them price 45- and 60-day locks at the identical rate, which is why 60 days has become the default for purchases. It’s long enough to get an appraisal back, clear underwriting, and satisfy title, without asking the lender to gamble on rate movement for months.
Here’s the rough ladder most lenders follow:
- 30 days: cheapest, but only workable if your file is simple and your closing date is firm
- 45–60 days: the standard for purchases; usually no extra cost
- 90–120 days: extended lock, typically priced with points or a slightly higher rate
- 180 days and beyond: new construction, renovation loans, and “lock and shop” programs, almost always at a premium
Refinances usually run shorter. If you’re locking a refinance, a 30- or 45-day window covers most files because there’s no seller, no inspection contingency, and no moving date to coordinate.
Why a longer lock costs more
When a lender locks your rate, they’re taking on the risk that rates move against them before you close. On a 60-day lock that risk is small and priced into the base rate. On a 180-day lock it’s substantial, and the lender hedges it by charging you.
On a $400,000 loan, the difference between a 60-day and a 90-day lock is often 0.25 points, or $1,000 paid at closing. A six-month lock can run 0.5 to 1 point. Some banks advertise “free” extended locks, but look closely and you’ll usually find the cost baked into a rate that’s 0.125% to 0.25% higher. That sounds trivial until you do the math: an eighth of a point on $400,000 is roughly $500 a year in interest, or close to $15,000 over a 30-year term. Paying $1,000 upfront for the same protection is the better trade if you have the cash.
There are exceptions. Builder-affiliated lenders frequently offer long locks at competitive pricing because they want to keep the financing in-house. Some credit unions run seasonal promotions on 120-day locks. If you’re shopping in a quiet market, you may also find a lender willing to waive an extended-lock fee to win your business, which is a conversation worth having.
What happens if your lock expires before closing
This is where locks get expensive. If your closing slips past the expiration date, you have three options, and none of them are pleasant:
- Extend the lock. Extension fees are commonly quoted as a percentage of the loan amount per week, often around 0.125%, which is roughly $500 a week on a $400,000 loan.
- Relock at current pricing. Most lenders will relock you at the worse of your original rate or the market rate that day.
- Let it float. You close at whatever the market offers, with no protection at all.
The good news is that extension fees are not always fixed in stone, especially when the delay is the lender’s fault. Appraisal backlogs, slow condo questionnaires, and underwriting requests that appear at the last minute are all legitimate grounds to ask for a waiver. There’s more on that in this guide to negotiating mortgage rates and lock terms, and it’s worth reading before you sign anything.
Float-downs: the safety net for a long lock
A float-down lets you capture a lower rate if the market improves during your lock period, usually once and usually only if rates drop by a set amount such as 0.25%. Most lenders charge 0.25 to 0.5 points for the feature, though a few include a one-time float-down for free as a competitive sweetener.
Long locks pair naturally with float-downs. If you lock for 120 days because you’re buying new construction, a float-down means you’re protected on the downside without being fully locked out of a rally. Just read the trigger terms carefully. Some float-downs only apply in the final 30 days of the lock, which limits how much you actually gain.
Adjustable-rate mortgages work differently again. Lock periods and caps on ARM mortgage rates interact in ways that aren’t always obvious, so ask specifically how a float-down applies to the fixed portion of an ARM before you commit.
How to pick the right lock length
Work backwards from your closing date, then add a buffer. A typical purchase takes 30 to 45 days from contract to closing, but the following can stretch it:
- Appraisal turnaround in a busy market, which can run three to four weeks on its own
- Condo or HOA document review, often the single biggest source of delay
- Title issues such as an unreleased lien or a missing heir
- Gift funds, self-employment income, or any file that needs a second round of underwriting
If you’re buying new construction, the builder’s completion date is an estimate, not a promise. Weather, permits, and material delays routinely push closings by weeks. A 30-day lock in that situation is a trap. This is the one scenario where a 180- or even 360-day lock generally justifies its cost, and many builders structure their financing around exactly that.
There’s also a pre-lock step worth taking. Anything you can do to strengthen your profile before you lock, such as paying down a revolving balance or disputing an old collection, can move your rate enough to beat whatever a longer lock would have saved you. These six moves that improve your mortgage rate are usually worth more than an extra 30 days of protection.
Questions to ask before you commit
The lock itself is negotiable, but only if you raise it before you sign. Get answers to these in writing, ideally from at least three lenders quoted on the same day:
- What’s the rate and point cost at 30, 45, 60, and 90 days?
- What does an extension cost, and is there a cap on how many extensions I can buy?
- Does the lock cover just the rate, or also the points and lender credits?
- Is there a float-down, what triggers it, and what does it cost?
- What’s the relock policy if my closing falls through and I come back in 60 days?
The rates you’re quoted on a 60-day lock today may look very different from what a 90-day lock costs, and the gap isn’t always where you’d expect. Comparing real quotes side by side, including how each lender handles lock pricing on conventional loans, is the only reliable way to know whether the extra protection is worth the premium.
One last thing worth internalising: the length of your lock should match the length of your risk, not your optimism. If there’s any real chance your closing slips, pay for the buffer now. An extension fee charged in the final week of escrow, when you have no leverage and no time, is the most expensive way to buy the same protection you could have had upfront for a fraction of the cost.