Quick answer
A mortgage rate lock generally protects an agreed interest rate between the lock date and closing, provided the loan closes before expiration and the application does not materially change. Confirm the lock status and expiration on page 1 of the Loan Estimate, obtain the lender’s written policy, and ask about extension pricing before the schedule becomes tight.
What a mortgage rate lock does
Mortgage rates can move while a buyer is under contract and the lender completes underwriting. A rate lock, sometimes called a lock-in, sets the loan’s pricing for a specified period under stated conditions. If the transaction closes on time and the application remains consistent, market movement alone generally should not change the locked rate.
A lock is not the same as final loan approval. Income, assets, credit, appraisal, title, insurance and other closing requirements still need to be completed. It also does not promise that every fee is fixed. Review the whole Loan Estimate and any written lock confirmation.
Where to find the lock status
At the top of page 1, the Loan Estimate indicates whether the interest rate is locked and, when locked, the date and time the lock expires. Save every Loan Estimate version so you can see whether the status or pricing changed.
Record these details
- Lock date, expiration date and exact expiration time
- Interest rate, points or lender credits and loan product
- Required closing date and current underwriting milestones
- Written extension policy, available periods and price
- Any float-down option and its conditions
The Loan Estimate versus Closing Disclosure guide explains which documents to compare before signing.
How long should the lock period be?
The CFPB notes that locks are commonly available for 30, 45 or 60 days, sometimes longer. Availability and cost vary by lender and transaction. A longer period can create more schedule protection but may carry different pricing. A shorter period can be risky if the appraisal, repairs, title work or underwriting are not far enough along.
Work backward from the contractual closing date and add time for final approval and document preparation. Ask the lender whether weekends, holidays and the funding date affect expiration. For a refinance, also account for any applicable rescission period and the lender’s funding process.
Why a locked rate can still change
The CFPB identifies application changes that can affect locked pricing, including a different loan amount or product, a changed down payment, an appraisal result, a changed credit score or income that cannot be documented as expected. The written lock agreement controls the specific transaction.
- Avoid opening new credit or making unexplained large financial changes before closing.
- Send requested documents promptly and keep proof of delivery.
- Tell the lender before changing the loan amount, down payment or product.
- Ask for a revised Loan Estimate when a valid change affects pricing.
- Compare points, credits and cash to close after every revision.
What happens if the lock expires?
If closing is delayed, the lender may offer an extension, relock the loan under then-current pricing or apply another policy described in the agreement. An extension can have a dollar fee, a pricing adjustment or a higher rate. Responsibility may depend on why the delay occurred and on the lender’s policy—not merely on which party feels responsible.
Ask for the extension choices in writing. Compare the extension cost with the effect of a different rate or credit, and confirm the new expiration. If another party caused the delay, review the contract and obtain qualified advice before assuming reimbursement is available.
A practical lock-management timeline
- Before locking: compare multiple written offers using the same loan scenario.
- At lock: save the confirmation and verify the Loan Estimate.
- Two weeks before expiration: ask which conditions remain and whether the closing schedule is realistic.
- One week before expiration: request written extension choices if any item is unresolved.
- Before signing: compare the Closing Disclosure with the locked terms and investigate unexplained changes.
Include lock costs in the cash-to-close comparison. If points or lender credits move with the lock, use the pricing tradeoff guide.
Questions to ask before locking
- Is this rate locked now, and can you send written confirmation?
- What date and time does the lock expire?
- Which changes can alter the rate, points or credits?
- What extension lengths are available and how are they priced?
- What happens if rates fall after I lock?
- Who monitors the deadline and when will I receive a warning?
Frequently asked questions
Does receiving a Loan Estimate mean my rate is locked?
No. Check the lock box on page 1. Lenders may issue a Loan Estimate before or after a lock.
Can a rate lock be extended?
Often, but availability and cost depend on the lender’s written policy and market conditions. Ask before expiration.
Does a rate lock guarantee closing?
No. It addresses rate pricing for a period; underwriting, property and closing requirements still apply.
Sources
- CFPB: What is a mortgage rate lock?
- CFPB: Explore the Loan Estimate
- CFPB: Compare the Loan Estimate and Closing Disclosure
Sources were checked on July 28, 2026. Policy terms, lending practices, product availability and state or local requirements can change.