Mortgages guide
Mortgage Rate Lock: What It Covers and What to Ask
A mortgage rate lock is an agreement intended to hold a quoted interest rate for a defined period while a loan moves toward closing. The protection usually depends on closing within the lock period and on the application staying materially consistent. Ask the lender for the exact terms, expiration date, extension cost, and rules if rates fall or your application changes.
What a lock is designed to do
Mortgage rates can move between application and closing. A lock can limit that rate movement for the agreed period, which may help you plan the principal-and-interest payment. A lock does not guarantee loan approval, freeze property taxes or insurance, or cover every fee. Review the Loan Estimate and separate written lock agreement.
Check the term and expiration date
The lock period must cover the expected time to close, including possible delays. Ask when the clock begins and the exact date and time it expires. An extension may cost money or require different terms. A short lock can be less expensive but may expire before closing; a longer lock may carry different pricing.
Know what can change the locked offer
Changes to the loan amount, down payment, property appraisal, credit, verified income, or loan type can affect pricing under the lender’s terms. A lock can also leave you unable to take advantage of a lower market rate unless the agreement includes a float-down feature. Ask for examples in writing instead of assuming a lock is unconditional.
Compare offers on the same basis
Suppose two lenders quote the same principal and term, but one offers a lower rate with a fee to lock longer. Compare the payment difference, upfront cost, expiration risk, and total loan costs. The principal-and-interest formula estimates only the payment under each rate; it does not value the lock’s contractual protection or predict future market rates. For a $300,000 loan, weigh even a small payment difference against the lock fee and expected time in the loan, using written same-day offers.
Questions to ask before agreeing
Ask whether the rate is currently locked, how long it lasts, what it costs, how extensions work, what application changes can reprice the loan, and what happens if rates decrease. Also ask whether points are tied to the locked rate and what must happen before closing. Save the answers and lock confirmation with your Loan Estimate. A written answer makes it easier to compare a $1,500 extension fee with a separate offer that has different pricing and timing.
Use a payment estimate as a check
Enter the quoted loan amount, rate, and term in a mortgage or loan calculator to estimate principal and interest. Add taxes, insurance, mortgage insurance, and HOA dues separately. Compare the estimate with the lender’s projected payment and ask about any difference; the calculator cannot verify a lender’s lock agreement.
Frequently asked questions
Does a rate lock guarantee the loan is approved?
No. It addresses rate terms under the lock agreement; underwriting and closing conditions still apply.
Can my locked rate change?
It can change if agreement conditions are not met or application details change. Read the lock terms and ask the lender.
Sources and further reading
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Educational content only; not individualized financial, tax, or legal advice.