Mortgage Rate Lock: Definition, How It Works, Periods, and Fees

Adam Hayes, Ph.D., CFA, is a financial writer with 15+ years Wall Street experience as a derivatives trader. Besides his extensive derivative trading expertise, Adam is an expert in economics and behavioral finance. Adam received his master's in economics from The New School for Social Research and his Ph.D. from the University of Wisconsin-Madison in sociology. He is a CFA charterholder as well as holding FINRA Series 7, 55 & 63 licenses. He currently researches and teaches economic sociology and the social studies of finance at the Hebrew University in Jerusalem.

Updated February 12, 2024 Reviewed by Reviewed by Erika Rasure

Erika Rasure is globally-recognized as a leading consumer economics subject matter expert, researcher, and educator. She is a financial therapist and transformational coach, with a special interest in helping women learn how to invest.

Fact checked by Fact checked by Rebecca McClay

Rebecca McClay has 10+ years of experience writing and editing content. Rebecca is an expert in personal finance, business, and financial markets.

What Is a Mortgage Rate Lock?

A mortgage rate lock is an agreement between a borrower and a lender that allows the borrower to lock in the interest rate on a mortgage for a specified time period at the prevailing market interest rate. A loan lock provides the borrower with protection against a rise in interest rates during the lock period.

The lender may charge a lock fee, which the borrower must pay if they do not lock the interest rate. Alternatively, the lender may charge a marginally higher interest rate to begin with, just in case the borrower chooses not to lock the interest rate.

Key Takeaways

Explaining a Mortgage Rate Lock

When a borrower locks in an interest rate on a mortgage, it is binding for both the borrower and the mortgage lender. The interest rate is locked for the period from the offer of the loan to its closing. The rate will stay consistent, regardless of market changes, as long as there are no changes to the application for the loan during the closing period.

If there is new or corrected information on your income or credit score, or if the loan amount changes, the mortgage interest rate could be affected regardless. Furthermore, if you change the type of mortgage you are seeking or if the appraisal of the home is lower or higher than anticipated, the interest rate may change.

If rates go down, you may have the option to withdraw from the agreement. The probability of such a withdrawal is known as a fallout risk for the lender. You ensure that the lock agreement allows for withdrawal.

In cases where prevailing rates decline during the lock period, you may have the option to take advantage of a float-down provision to lock in a new, lower rate. As with any feature that increases interest-rate risk to the lender, a float-down provision generally entails an additional cost.

Mortgage locks generally last for 30 to 60 days. At a minimum they should cover the period necessary for the lender to process your loan application. An example of a short lock period is one that expires shortly after completion of the loan-approval process. In some cases this lock period can be as short as a few days.

You can negotiate the terms of a loan lock and often extend the term of the lock for a fee or slightly higher rate.

Risks of Taking on a Mortgage Rate Lock

A downside, for the borrower, is a mortgage rate lock would prevent them from taking advantage of lower rates that may occur during the lock period. Conversely the lender cannot take advantage of rises in interest rates.

Some borrowers walk away from the agreement if interest rates fall. And unscrupulous lenders have been known to let lock periods expire if interest rates rise under the excuse that the borrower could not process the necessary paperwork in time.

A lock deposit requirement indicates that both the borrower and the lender intend to keep the agreement. A rate lock may be issued in conjunction with a loan estimate.

A mortgage rate lock period could be an interval of 10, 30, 45, or 60 days. If the period is longer, you may have a higher interest rate. Essentially the rate lock would be lower on shorter intervals till the close because there is less risk of fluctuation in the market. If the lock period expires and the mortgage has not closed, it may be possible to request an extension to the rate lock.

If an extension is not granted, then the mortgage will be subject to the going market rates.

Even with a rate lock and a mortgage rate lock float down, it is possible to end up paying a higher interest rate than the rate that you agreed to when you signed for the lock. This occurs because many lenders include a "cap" with the lock agreement. The cap permits the guaranteed rate to rise if interest rates rise before settlement. Because the cap sets a limit on the amount the rate can rise, it does provide some protection against rising interest rates.

What if I Lock in a Rate and it Goes Down?

If you lock in a rate, you can only take advantage of a lower interest rate if you have a float down provision that allows you take the lower of the two interest rates. Otherwise, you will have to take the rate you locked in with the lender or withdraw from the agreement.

How Do You Include a Float Down Provision in a Rate Lock?

You can include a float down provision when you lock-in a mortgage rate by paying any associated fees with this benefit. The fee will vary by lender but can be up to about 1% of the loan.

Can You Negotiate Your Loan Terms at Closing?

You can negotiate the terms of your loan until you officially close the loan by signing the documents. You can also negotiate the costs of the mortgage up until that point. Keep in mind lenders are not obliged to make changes to the agreed-upon terms.

Bottom Line

A mortgage rate lock can be valuable in a mortgage application process, especially when interest rates are rising. With this feature, you can secure one interest rate for your loan even if interest rates increase with broader market trends before your mortgage closes. Consider the current interest market rate trends and your financial situation to determine if a mortgage rate lock is right for you.

Article Sources
  1. Consumer Financial Protection Bureau. "What's a Lock-in or a Rate Lock on a Mortgage?"
  2. Nasdaq. "Fallout Risk."
  3. Consumer Financial Protection Bureau. "Am I Allowed to Negotiate the Terms and Cost of My Mortgage?"
  4. Rocket Mortgage. "Float-Down Option: Can It Lower Your Mortgage Rate?."
Related Terms

Modifying a mortgage and refinancing can make your payments more affordable. Learn how each option works.

A mortgage originator is an institution or individual that works with a borrower to complete a mortgage transaction. Originators are part of the primary mortgage market.

An adjustment frequency refers to the rate at which an adjustable-rate mortgage rate (ARM) is adjusted after the initial, fixed-rate period has expired.

A dry loan is a mortgage where the funds are exchanged only after all of the required sale and loan documentation has been completed.

The purchase mortgage market is the portion of the primary mortgage market devoted to loans for new home purchases.

The National Reverse Mortgage Lenders Association (NRMLA) is a professional organization that serves the reverse mortgage industry through education and policy advocacy.

Related Articles

A woman in a black shirt and jeans sits barefoot on the floor with a laptop and paperwork

Found a Good Mortgage Rate? Lock It in! Compare the Best Mortgage Rates Today - Sept. 19, 2024 Compare the Best Jumbo Mortgage Rates for 2024

Couple meeting with loan officer

Mortgage Modification vs. Refinance: Which Is Right for You?

Senior couple going over their finances at the kitchen table

Reverse Mortgage vs. Selling Your Home

Older couple speaking with a mortgage originator

Mortgage Originator: Definition, What It Does, Types Partner Links Investopedia is part of the Dotdash Meredith publishing family.

We Care About Your Privacy

We and our 100 partners store and/or access information on a device, such as unique IDs in cookies to process personal data. You may accept or manage your choices by clicking below, including your right to object where legitimate interest is used, or at any time in the privacy policy page. These choices will be signaled to our partners and will not affect browsing data.

We and our partners process data to provide:

Store and/or access information on a device. Use limited data to select advertising. Create profiles for personalised advertising. Use profiles to select personalised advertising. Create profiles to personalise content. Use profiles to select personalised content. Measure advertising performance. Measure content performance. Understand audiences through statistics or combinations of data from different sources. Develop and improve services. Use limited data to select content. List of Partners (vendors)