Locking In a Mortgage Rate: Lengths, Float-Downs, and Expiration

A mortgage rate lock is a lender’s written promise to hold a specific interest rate and point structure for you while your loan is being processed, typically for 30 to 60 days.¹ Because mortgage rates can shift daily, locking protects you from paying more if rates climb between application and closing. The tradeoff is that a lock also prevents you from benefiting if rates fall, unless you negotiate a float-down option in advance.

What a Rate Lock Actually Freezes

A lock freezes two things: your interest rate and your discount points. Points are prepaid interest, where one point equals one percent of the loan amount.² If you lock at 6.75% with one point on a $400,000 loan, the lender guarantees that rate and the $4,000 point charge no matter what the bond market does over the next several weeks.

The lock does not cover everything on your Closing Disclosure. Appraisal fees, title insurance, homeowner’s insurance quotes, and property tax estimates all move independently. Your monthly payment can still shift after you lock because those non-interest costs aren’t part of the agreement. Treat a rate lock as a ceiling on the interest-related piece of the transaction, not a freeze on every dollar involved.

When to Lock and When to Float

You don’t have to lock the moment you apply. Some borrowers choose to “float,” meaning they let the rate move with the market until they decide to lock.³ Floating cuts both ways. If rates drop, you benefit. If rates spike, you’re stuck with a higher payment for the life of the loan.

There is no universally right moment to lock. Some lenders let you lock at application; others wait until your loan is approved. A practical rule: if you’ve found a rate you can comfortably afford and the lock window covers your expected closing timeline, lock it. Trying to time the bottom of a rate cycle is speculation, and the downside is steeper than most buyers budget for. If you’re genuinely worried rates will drop further, ask about a float-down option before you lock rather than leaving the rate exposed.

How to Request the Lock

Lenders need several things settled before they’ll commit. You need a specific property address, a chosen loan program (a 30-year fixed or a 5/1 adjustable, for example), and a verified credit score, since your score determines which pricing tier you qualify for. Have your income documentation ready, including recent pay stubs and tax returns, so the lock matches the loan amount the lender ultimately approves.

With those pieces in place, you submit a lock request through the lender’s online portal or through your loan officer. The lender executes the lock in their pricing system at the current market rate and issues a written confirmation. Get that confirmation in writing. It should show the locked interest rate, the number of points, any lock fee, and the expiration date.³ A verbal promise is nearly impossible to enforce later.

Federal rules also require your lender to send a revised Loan Estimate within three business days after the rate is locked, reflecting the updated interest rate, points, lender credits, and any other rate-dependent charges.⁴ Compare that revised estimate against your lock confirmation and make sure the numbers match. Discrepancies caught early are easy to fix. Discrepancies caught at closing are not.

Lock Lengths and What They Cost

Standard locks run 30, 45, or 60 days.¹ Some lenders offer windows as short as 7 days after loan approval, and others go as long as 120 days for buyers who need more runway.³ The general rule is that longer locks cost more, because the lender is absorbing more market risk on your behalf.

Lock fees take several forms. Some lenders charge nothing for a standard 30-day lock and build their compensation into the rate itself. Others charge a flat fee, a percentage of the loan amount, or add a fraction of a point to the quoted rate.³ A 60-day lock will almost always cost more than a 30-day lock at the same lender. Whether the fee is refundable if the loan doesn’t close varies, so ask before you commit.

Locks for New Construction

Buyers purchasing a home that’s still being built face a timing problem, because construction can take 6 to 12 months, well beyond a normal lock window. Some lenders offer extended locks for new construction, protecting your rate for up to 12 months. These typically cost more than a standard lock through a higher rate, an upfront deposit, or both. They usually include a one-time float-down option so you aren’t penalized if rates fall substantially during construction. Ask about extended-lock programs early, because not every lender offers them.

Float-Down Options

A float-down lets you reduce your locked rate one time if market rates drop after you lock. It sounds like free insurance, but there are conditions. Most lenders require rates to fall by a minimum amount before you can exercise the option, often around 0.5%, though each lender sets its own trigger. Some charge an upfront fee for the privilege, and the adjusted rate you receive is usually not as low as what a brand-new borrower would get off the street. On a large loan, even a modest reduction can save thousands over the life of the mortgage. Ask your lender for the specific threshold and any fees before you lock.

What Can Void Your Locked Rate

A rate lock is not unconditional. Your locked rate can change or disappear if the underlying facts of your application shift. The CFPB identifies several common triggers:¹

Credit score changes. Opening a new credit card, missing a payment, or taking on other debt during underwriting can drop your score below the threshold for your locked pricing tier.
Loan program or down payment changes. Switching from a fixed-rate to an adjustable-rate mortgage, or changing your down payment, creates a fundamentally different loan that voids the original lock.
Income verification problems. If your lender cannot document overtime, bonus, or other income you reported, your approved loan amount may change, and the lock no longer applies to the revised terms.
Appraisal surprises. An appraisal that comes in significantly higher or lower than expected can alter the loan-to-value ratio, which changes your pricing.

The most common way to lose a lock is doing nothing wrong at all: letting the clock run out. If your loan doesn’t close before the lock expires, the lender is released from the agreement.³ Pad your lock period by at least a week beyond your best-case closing estimate.

If Your Lock Expires Before Closing

When a lock expires, you’re back to market rates. Most lenders will offer you the prevailing rate at the time of expiration, which could be noticeably higher than what you originally locked.³ You generally have two options:

Extend the lock. Pay a fee to keep your original rate for an additional period. Extension fees commonly range from 0.25% to 1% of the loan amount, though some lenders charge a flat fee. On a $400,000 loan, that’s $1,000 to $4,000 for perhaps another 15 to 30 days of protection.
Relock at current rates. Accept whatever the market offers. If rates dropped, this works in your favor. If they climbed, you absorb the increase.

If the delay was the lender’s fault rather than yours, many lenders will waive the extension fee. There’s no federal rule requiring this, but it’s standard industry practice and worth pushing for. Document every delay on the lender’s side so you have leverage if they resist.

Before you lock, ask your lender two questions the Federal Reserve specifically recommends: what rate will be charged if the lock expires, and whether the lender will refund any fees if you cancel the application after expiration.³ Clear answers upfront prevent expensive surprises if your closing runs long.

1
Consumer Financial Protection Bureau. What’s a Lock-In or a Rate Lock on a Mortgage?
2
Consumer Financial Protection Bureau. How Should I Use Lender Credits and Points (Also Called Discount Points)?
3
Federal Reserve Board. A Consumer’s Guide to Mortgage Lock-Ins
4
eCFR. 12 CFR 1026.19 – Certain Mortgage and Variable-Rate Transactions