Mortgage rates · Guide

Mortgage Rate Locks Explained

What a rate lock is, how long it lasts, what it costs and what happens if your closing is delayed.

  • Cites official sources
  • No forms, no tracking
  • Not a lender

Key takeaways

  • Common lock periods range from a couple of weeks to two months, and longer locks are usually priced higher because the lender carries market risk longer. Lock periods
  • If closing is delayed, a lock extension may carry a fee. Extensions and float-downs
  • No one can reliably predict short-term market moves. When to lock

What a lock does

A rate lock is a lender’s commitment to hold a specific interest rate and price for a set number of days while your loan is processed, as long as your application details do not change.

Lock periods

Common lock periods range from a couple of weeks to two months, and longer locks are usually priced higher because the lender carries market risk longer. New construction loans may offer extended locks.

What can change a locked rate

  • A lower appraisal that changes your loan-to-value.
  • A change in credit score, income or loan amount.
  • Missing the lock expiration date.

Extensions and float-downs

If closing is delayed, a lock extension may carry a fee. Some lenders offer a float-down option that lets you capture a better market price once during the lock, sometimes for a fee. Get any lock agreement in writing.

When to lock

No one can reliably predict short-term market moves. Many borrowers lock once they have a signed purchase contract or a refinance application and a closing timeline they can meet.

Updated · Sources reviewed

This page is general education. Program rules change; confirm current requirements with the official sources linked here and with a licensed lender.

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Your path through this site

Prefer one page? Mortgage pricing basics gathers every guide, calculator and key term in reading order.

  1. Learn what drives your priceRead Lock Timing for Purchases vs. Refinances, then Lock Extensions, Relocks and Float-Downs.
  2. Test scenariosPayment and amortization shows how your own inputs change the result.
  3. Check which programs fitAnswer six questions to see which loan programs to read about.
  4. Compare quotes the right wayRequest Loan Estimates on the same day and compare them with the checklist.

Explore

Guides on this site

Lock Timing for Purchases vs. Refinances

How lock strategy differs when you have a contract closing date versus a flexible refinance.

Lock Extensions, Relocks and Float-Downs

What happens when a rate lock is about to expire, and the options lenders commonly offer.

When Closing Gets Delayed: Rights and Next Steps

Common causes of mortgage closing delays, what disclosures change, and how to protect your purchase contract.

A Rate Lock Decision Checklist

How to think through when to lock, how long a lock you need and what to ask about extensions, before you commit.

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Glossary

Terms these guides use

Float-down
A lock option allowing a one-time price improvement if the market moves.First used in Lock Timing for Purchases vs. Refinances
Loan Estimate
The standardized three-page form a lender must provide within three business days of application.First used in Lock Timing for Purchases vs. Refinances
Rate lock
A lender’s commitment to hold a rate and price for a set period.First used in Lock Extensions, Relocks and Float-Downs
Appraisal
An independent opinion of market value used by the lender.First used in Lock Extensions, Relocks and Float-Downs

All 20 terms, A to Z