Knowing when to lock in a mortgage rate comes down to three things being true: the numbers work for you, your closing date is known, and a rate move against you would hurt more than a missed improvement would sting. When all three line up, lock. Everything else in this article is about testing those three honestly, because the borrowers who get hurt are almost never the ones who locked early. They are the ones who floated on somebody's confident forecast. A listener's loan was approved and sitting ready to lock at 6.125% during a rate dip, and his loan officer insisted rates were headed lower and kept him floating. By the time he reached out to us, the same loan priced a half percent higher, on a $750,000 balance. No refund window exists for that mistake, which is why the lock deserves more attention than the quote.
Everyone tells us the same thing on inquiries: I want the lowest rate. Fair. But the lowest rate is won or lost in how the lock is handled, and Josh has been making these calls with borrowers since 1995. These are the five questions we walk through every time, and the mechanics behind them, lock periods, costs, extensions, and expirations, are covered separately in our guide to how a mortgage rate lock works. This article is the decision itself.
A lock is the lender's commitment to close your loan at a set rate and cost within a set window. Floating means staying exposed: if the market improves you win, and if it turns you absorb the damage. Whether floating is even on the table starts with temperament, and in our experience maybe one or two borrowers in ten are genuine gamblers, while roughly half want the risk gone the moment they hear the question.
There is also an asymmetry worth respecting. Borrowers who lock and then watch rates drift down an eighth are mildly bummed. Borrowers who float and watch rates jump a half percent lose their minds. Missed gains sting; realized losses hurt, and they hurt disproportionately. Jeb floated his own refinance to the last possible minute betting on one more dip, the dip never came, and he took a higher rate than he could have locked, with decades of market experience and a shelf full of technical analysis books behind the decision. Gamblers lose hands too, and you have to be genuinely okay with that before you play one with your house payment. If one ugly afternoon in the bond market would ruin your week, lock, and put the energy into inspections and loan conditions instead.
Nobody has a crystal ball. Us included. The useful version of this question is about your sources, because a loan officer speaking in certainties is a warning sign, and the classic line is some version of: wait until the 18th, the Fed is meeting and rates will drop. A Fed cut does not mean mortgage rates fall; they often do the opposite in the days around a meeting, and we broke down why in whether the Fed rate affects mortgage rates.
What actually moves rates week to week is data, inflation and jobs reports above all. If you are two days from needing to lock and a jobs report lands tomorrow morning, that report belongs in the conversation, and sometimes the right move is locking ahead of a coin flip you do not need to take. Josh's team pays for multiple professional rate analyses and treats every one of them as odds rather than answers: a good read can say the market favors waiting a few days, and it cannot promise the next report goes your way. Watch your own bias too. When you want lower rates, you will notice every forecast that promises them and scroll past every one that does not. And give credit to the loan officer who says plainly that forecasting is not their job; an honest no-crystal-ball beats confident nonsense every time.
Shorter locks price better, so the goal is the shortest lock that genuinely covers you through closing. On a purchase, the contract mostly answers this: closing on the 15th, 36 days out, means a 45-day lock at most lenders, or a custom 38-day lock at the ones that price to the exact day. (The policy figures in this article, lock increments, extension costs, and document shelf life, reflect common lender practice as of this episode, 1/20/2025; every lender writes its own rules, so confirm yours before locking.)
Then adjust for red flags that stretch timelines: new construction, which is notorious for pushed closings; a tenant-occupied property where access for inspections and the appraisal keeps slipping; a contentious negotiation that is still going back and forth. On a refinance the sizing is the lender's job, and a good one will tell you which file they are holding: a clean loan with an appraisal waiver can close in 17 to 21 days and earn the cheaper short lock, while a jumbo needing two appraisals and a second underwrite needs 30 to 45.
One point of accountability we hold ourselves to, and you should hold your lender to: the lock term quoted should be days the lender knows they can hit, never a best-case scenario. If a loan officer quotes 17 days to win the pricing comparison and the loan takes 21, the extension cost belongs on the lender, and even a four-day extension carries real basis points.
A single rate is one point on a curve. Before you lock, you want the menu: the zero-point rate, what a quarter or half percent lower costs in points, and what credit you would receive for taking a notch higher. The trades are not always symmetrical, and occasionally they are lopsided in your favor. A listener we quoted on a refinance asked to see lender credit options, and the answer was a $2,800 credit toward closing costs in exchange for a payment $17 a month higher. That is a decision worth sixty seconds, and it only happens when the menu is on the table before the lock. We covered the mechanics of that trade in lender credits explained.
This is also the moment to understand why your quote differs from the number in a headline. The averages quoted in the news assume one borrower profile, and your rate is built from your file: credit score, down payment, lock length, property type (a condo with less than 25% down prices higher), and in expensive counties a high-balance loan amount can add a quarter to three eighths on its own. The same logic exposes the online teaser trap: the fine print under a bank website's rate usually assumes an 800 score, 60% loan-to-value, and discount points baked in, and we have seen large online lenders advertise rates on zero-down programs that carry about a point and a half of discount points in the fine print. Actually check the asterisk. Then compare lenders the only fair way, same day, same lock term, same program, which we walk through in how to compare mortgage offers.
A lock is contractual. The lender does not get to call and say they changed their mind; if pricing moves on a locked file, they must point to a specific fact that changed. The realistic ones are worth knowing in advance. The appraisal is the big one: a refinance that assumed a $1,000,000 value on a $700,000 loan locks in a 70% loan-to-value pricing band, and an appraisal at $900,000 pushes the loan to 78%, where the pricing cells are worse. Credit documents also age: reports are typically good for about 120 days, and on a long escrow a required re-pull that comes back 15 or 20 points lower can reprice the file. Rare, but real. The defense is boring behavior: no new accounts, no unexplained money movement, close on time.
There is no ceremony. You tell your loan officer to lock, verbally is fine, and the terms are set. The proof arrives in writing: federal disclosure rules require an updated Loan Estimate within three business days of locking, and it states the rate, the points in section A, and the date the lock expires. Many lenders also send a lock-in agreement spelling out the same terms; a nice confirmation, but the locked Loan Estimate is the required document. A verbal quote, no matter how confident, is never a lock.
The mistakes we see repeat themselves: floating on hope, because hope is not a strategy; assuming a quoted rate is a locked rate; blowing through a lock expiration because nobody compared the closing date to the lock date; and mid-escrow changes that hand the lender a legitimate reason to reprice. One more that deserves its own answer: locking is never a trap if rates fall afterward, because most lenders will renegotiate a locked rate when the market improves enough, and we wrote can you renegotiate your mortgage rate to cover exactly when and how.
Five questions, one theme: the lock is a strategy decision, and it should be built around your closing date, your qualification headroom, and your sleep. Penciling that strategy for your specific file, which data weeks matter, how long to lock, what the points-and-credits menu looks like, is exactly what we work through on a free Roadmap call: about 20 minutes, and you leave knowing your numbers and your lock plan instead of hoping the market behaves.
Stop guessing what you can really afford
Tell Josh and his team your situation, and you'll get the exact price range you qualify for, the loan that gets you the most home for your money, and a step-by-step plan to close. They handle your loan directly, never a referral, and go far beyond a basic pre-approval, so you stop second-guessing, tour with confidence, and write offers sellers take seriously.
Build my Roadmap →As soon as the payment works for you, your closing date is known, and you would rather have certainty than a bet, which describes most borrowers. On a purchase you can generally lock once you have a property under contract; on a refinance, once you commit to moving forward. Waiting is only rational when you have genuine risk tolerance and a defensible read on the next one to three weeks, never on a hunch or a loan officer's confident forecast.
Start with your temperament. Roughly half of borrowers hate risk, and for them locking and ignoring daily rate noise is the right call almost every time. Floating only suits genuine gamblers who accept they can lose, because the downside of floating into a rate spike far outweighs the upside of catching a small dip. Whatever you choose, decide deliberately with your lender rather than drifting unlocked by default.
The shortest term that genuinely covers you through closing, because shorter locks get better pricing. On a purchase, count the days to your contractual closing date and add a small cushion, more if the file has delay risk like new construction or a tenant-occupied property. On a refinance, a clean file with an appraisal waiver can close in 17 to 21 days, while complex loans need 30 to 45; your lender should size it honestly, not optimistically.
Only if a fact in your file changes. A lock is contractual, so the lender must point to a changed circumstance, most commonly an appraisal that comes in low and moves your loan-to-value pricing band, a credit report that expires on a long escrow and re-pulls with a lower score, or a program switch. Keep the file boring between lock and closing, no new debt or unexplained deposits, and the rate you locked is the rate you sign.
Get it in writing. Federal disclosure rules require an updated Loan Estimate within three business days of a lock, and it states whether the rate is locked, the points you are paying, and the expiration date. Many lenders also send a separate lock-in agreement, though it is not required. A verbal quote is never a lock, so if you have not seen a locked Loan Estimate, assume you are floating and ask your loan officer directly.