Mortgage Rate Locks: When to Lock, How Long, and What If Rates Drop

Mortgage rates change every day, sometimes several times a day. Between the moment your offer is accepted and the day you close, which is often 30 to 60 days, a rise in rates could push your payment up or even affect whether you still qualify. A rate lock is how you take that risk off the table.

This guide explains how rate locks work, how to choose a lock length, and what to do if rates fall after you lock or your closing gets delayed.

What a rate lock is

A rate lock is a lender's commitment to give you a specific interest rate, with specific points, for a set period, as long as your application doesn't change materially. The CFPB explains that a lock protects you if rates rise before closing, but that a lock also usually means you won't benefit if rates fall, unless you have a float-down option.

Things that can void or change a lock include changes to your loan amount, credit score, income, the appraised value or your down payment. If any of these shift, the lender may reprice your loan.

Why locking matters: a worked example

As of October 29, 2026, the 30-year fixed average was 7.24%. Suppose you're borrowing $353,970, which is 10% down on the national median home price of $393,300 (Q3 2026). If rates rose half a point before you closed:

That's about $121 more per month for the life of the loan, and the higher payment could also push your debt-to-income ratio over a lender's limit. A lock prevents this.

When to lock

Most buyers lock once they have:

1. A signed purchase contract with a known closing date.
2. A lender chosen after comparing Loan Estimates. See how to compare mortgage rates.
3. A rate and points combination they're happy with.

Some lenders will let you lock before you have a property, sometimes with conditions; ask about it if you're worried about rising rates during a search.

Trying to time the bottom of the market is a gamble. Rates can move in either direction, and nobody can predict short-term moves reliably. If the payment works for your budget, locking gives you certainty.

How long to lock

Common lock periods are 30, 45 and 60 days, and some lenders offer longer locks. Longer locks protect you for more time but can come with a slightly higher rate or an upfront fee, because the lender carries the risk longer.

Choose a lock that covers your expected closing date plus a buffer. Delays are common: appraisals, title issues, repairs, underwriting conditions or a seller's moving plans can all push closing back. A lock that's too short could expire before you close.

Your lock's expiration date and terms should be in writing. The Loan Estimate shows whether your rate is locked and until when, on page 1.

If your lock is about to expire

If closing slips past your lock's expiration, you typically have options:

• Extend the lock, often for a fee or a small rate increase. Ask about costs up front.
• Relock at current market rates, which could be higher or lower than your original rate. Some lenders have relock policies that use the worse of the original or current rate.

Ask who pays for an extension if the delay is the lender's fault versus yours or the seller's. Get the answer in writing.

If rates drop after you lock

A standard lock generally holds the rate whether rates go up or down. Some options can help:

• Float-down option: Some lenders offer a one-time option to lower your rate if market rates fall by a set amount before closing, sometimes for a fee. Terms vary a lot; ask exactly how it works.
• Renegotiate: If rates fall significantly, a lender may agree to reprice rather than lose you to a competitor, but there's no guarantee, and switching lenders late can delay closing and cost you fees you've already paid, such as the appraisal.
• Refinance later: If rates fall a lot after closing, refinancing may make sense, though it comes with its own closing costs.

Rate locks and points

A lock covers a specific rate and a specific points or credits combination. If you later change how many points you're paying, the lender will reprice. Decide on points before you lock. Our points guide shows how to calculate the break-even.

Questions to ask your lender

• How long is the lock, and what's the exact expiration date?
• Is there a fee for this lock length?
• What does an extension cost, and who pays if the delay isn't my fault?
• Do you offer a float-down, and on what terms?
• What changes to my application would cause the loan to be repriced?

Common questions

Does locking cost money? Standard lock periods are often included in pricing, while longer locks or extensions may carry fees or a slightly higher rate. Ask for costs in writing.

Can I switch lenders after locking? Yes, but you'll typically start over with a new application and appraisal, which can delay closing and cost money. It's usually only worth it for a meaningful improvement.

What happens to my lock if the appraisal comes in low? A low appraisal can change your loan-to-value ratio, which may reprice your loan. You might renegotiate the price, add cash or change the loan structure.

Practical takeaways

• A rate lock protects you from rising rates between contract and closing.
• Lock once you have a contract, a chosen lender and a rate and points combination you like.
• Choose a lock period that covers your closing date with a buffer for delays.
• Understand extension costs and float-down terms before you lock.
• Watch rate trends on our rates page and test payments in the mortgage calculator.

Sources

• CFPB: What is a rate lock?
• CFPB: What is a Loan Estimate?
• CFPB: Explore interest rates
• Freddie Mac Primary Mortgage Market Survey

Rates and prices are as of the dates noted and will change. This article is for education only and is not financial advice.