A mortgage rate lock is an agreement that protects specified interest-rate pricing for a limited period while the loan moves toward closing, as long as the transaction closes on time and the information or terms used to price the loan do not materially change.
A lock usually covers the interest rate and related points or lender credits shown in the lock confirmation. It does not freeze every closing cost, property tax, insurance premium, escrow amount, or third-party charge.
The Loan Estimate includes a rate-lock section. When a rate has been locked after the initial Loan Estimate, federal disclosure rules generally require a revised Loan Estimate reflecting the locked rate and rate-dependent charges within the applicable time frame.
Review Mortgage Closing Costs Explained to separate rate-dependent pricing from other transaction costs.
There is no single correct day. A borrower generally needs a property address and enough transaction detail for the lender to lock a purchase loan. The decision depends on:
Trying to predict the lowest rate can create risk. A lock converts uncertain market pricing into defined terms for a defined period. Waiting preserves the chance of improvement but also accepts the risk of deterioration.
Lenders may offer periods such as 15, 30, 45, 60, 75, or 90 days, with longer periods often carrying different pricing. Construction, renovation, delayed-closing, and extended-lock programs can work differently.
Choose a period that provides a reasonable buffer beyond the expected closing rather than assuming every step will finish at the earliest possible date.
| Change | Possible effect |
|---|---|
| Credit score changes | Pricing, mortgage insurance, approval, or program eligibility may change |
| Loan amount or down payment changes | Loan-to-value ratio and price adjustments may change |
| Property or occupancy changes | A condominium, manufactured home, second home, investment property, or different property can have different pricing |
| Program or term changes | Changing from fixed to ARM, conventional to FHA, or 30-year to 15-year requires new pricing |
| Closing after expiration | An extension, relock, or worst-case pricing policy may apply |
| Information was inaccurate | The lender can reprice based on the correct transaction facts |
An extension keeps locked pricing in place beyond the original expiration. The lender may charge a fee, adjust pricing, absorb the cost, or allocate responsibility based on the reason for delay and its policy. The cost can depend on the number of days and current market movement.
Track the appraisal, underwriting, insurance, title, Closing Disclosure, and signing schedule before expiration. An extension discussion should happen before the lock ends, not after.
A float-down can allow a borrower to receive improved pricing after locking when the lender’s stated conditions are met. It is not a universal right. The agreement may specify:
A float-down does not necessarily produce the same pricing the borrower would receive by starting a new application elsewhere, and changing lenders can jeopardize contract deadlines.
Most purchase rate locks are property specific. Some lenders offer a lock-and-shop or pre-lock program before a property is selected, often with special time limits, extension rules, or fees. Verify whether the lock can transfer to a new address and what happens if no contract is signed.
New construction can require a longer lock because the completion date is uncertain. Extended locks may include upfront deposits, nonrefundable charges, float-down provisions, or extension costs. Review builder delay risk and certificate-of-occupancy timing before selecting the lock period.
A lock is an agreement with that lender, but it does not usually force a borrower to close the loan. Changing lenders can involve a new application, appraisal, disclosures, rate, costs, and timeline, and a lock fee may be nonrefundable under the agreement.
Only under the lender’s float-down, renegotiation, or pricing policy. A lock generally protects against increases but does not automatically pass along market decreases.
It should remain protected when the loan closes within the lock period and the priced facts do not change. Expiration, changed loan terms, inaccurate information, or another allowed change can affect pricing.
Not necessarily. Check the Rate Lock box on page one. If it says “NO,” the rate, points, and lender credits can change until the rate is locked.
Availability depends on the lender and market. Many lenders lock only when their pricing desk is open, though some offer limited after-hours or weekend processes.
Only when the loan can reasonably close within that period. A small initial benefit can be lost through extension costs or expiration risk.
Compare current pricing, lock length, points, credits, extension risk, property complexity, and your tolerance for market movement.
Reviewed September 2, 2026 by Michael Shotnik, Broker | Owner, Milestone Home Mortgage, LLC, NMLS 218281. Educational information only. Lock policies, fees, extensions, float-downs, relocks, market hours, and protected terms vary by lender and agreement. Obtain and review written lock confirmation.
Updated August 31, 2026
Builder mortgage incentives in Colorado can create real value, but the advertised rate or credit is only one part of the transaction. A builder may offer a permanent rate buydown, a temporary buydown, closing-cost assistance, a price reduction, design-center upgrades, or a combination ...
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Milestone Home Mortgage LLC NMLS #2588937. Michael Shotnik NMLS: 218281, CO License: 100017466. Not licensed in Alaska or New York. To check license status of mortgage loan originator, visit D.O.R.A. and NMLS consumer access.
