A mortgage rate lock is a lender commitment to hold a specific interest rate for a defined period while your loan moves through underwriting and closing. It matters because even a small rate change can affect monthly payment, debt-to-income ratio, and cash needed to close.
When Buyers Usually Lock
Most buyers lock after an accepted offer, once the lender has a property address, purchase price, loan amount, and expected closing date. Some lenders offer float-down options or lock-and-shop programs, but those terms vary. Ask whether the quoted rate is actually locked or only an estimate.
Lock Periods and Extensions
Common lock periods include 30, 45, and 60 days. Longer locks can cost more. If closing is delayed beyond the lock period, the lender may charge an extension fee or adjust pricing. Before signing, ask who pays for extensions if the delay is caused by the lender, seller, title issue, appraisal delay, or buyer documentation delay.
Points, Credits, and the Real Cost
The interest rate alone does not tell the whole story. A lower rate may require discount points paid up front. A slightly higher rate may come with a lender credit that reduces closing costs. Compare options by looking at monthly payment, cash to close, and how long you expect to own or refinance the home.
How much a small move matters
Rates move week to week. Freddie Mac’s weekly survey put the average 30-year fixed rate at 7.11% on November 12, 2026, down from 7.18% a week earlier and up from 6.24% a year before. On an illustrative $400,000 30-year loan, principal and interest is about $2,691 a month at 7.11%, $2,710 at 7.18% and $2,460 at 6.24%. Those are national averages, not a quote: your rate depends on your credit, loan type, points and the lender. The point is that a lock protects you from the next move in either direction for a set period.
Questions to Ask Your Lender
- Is this rate locked today or only quoted?
- How long is the lock period?
- What is the extension cost per day?
- Are points included in the quote?
- Is there a float-down option if rates improve?
- What conditions could change the rate after locking?
Rate locks are financing decisions, not predictions. Review options with your lender and buyer agent so your offer timeline, financing contingency, and closing date line up.
A lock is conditional
A change in your application can affect a locked rate. Ask the lender what happens if the loan amount, credit profile, income verification or closing date changes, and get the lock terms in writing.
CFPB explanation of rate locks · Freddie Mac Primary Mortgage Market Survey