What Is a Rate Lock?

A rate lock is a commitment from your lender to hold a specific interest rate and a set number of discount points for a defined period while your mortgage application is processed. Once you lock, your rate will not change regardless of what happens in the broader market — even if rates rise significantly before your closing date.

Rate locks exist because mortgage processing takes time. From application to closing, a conventional mortgage typically takes 30 to 60 days. During that window, market rates can shift by a quarter point or more. Without a lock, you would be at the mercy of daily fluctuations, and the rate you were quoted at application could look very different by the time you sit down to sign closing documents.

A rate lock is not the same as a loan commitment. The lock guarantees the rate, but your loan must still go through underwriting and approval. If your financial situation changes — for example, you take on new debt or your credit score drops — the lender may revoke the lock or adjust the terms. Understanding how mortgage rates are determined will help you appreciate why timing your lock matters so much.

Common Lock Periods

Lenders offer rate locks in several standard durations. The most common are 30, 45, and 60 days, though some lenders offer locks as short as 15 days or as long as 90 to 120 days. Each duration comes with its own pricing trade-off.

• 30-day lock: This is the shortest standard option and typically comes at the lowest cost — often at no additional charge above the quoted rate. A 30-day lock works best when you have already found a home, your offer has been accepted, and you are confident the closing process will move quickly. The risk is that any delays in appraisal, title work, or underwriting could push you past the expiration date, potentially requiring a costly lock extension.
• 45-day lock: The most popular choice for purchase transactions. A 45-day lock provides a comfortable buffer for the typical closing timeline while adding only a modest cost — usually around 0.125% higher than the 30-day rate, though this varies by lender. This duration balances protection and affordability for most borrowers.
• 60-day lock: Ideal for more complex transactions such as new construction purchases, transactions involving multiple contingencies, or situations where delays are likely. A 60-day lock generally costs about 0.125% to 0.25% more than a 30-day lock. While the premium is higher, the peace of mind can be worth it when your timeline is uncertain.
• Extended locks (90 to 120 days): Some lenders offer longer locks for new-build homes or complex closings. These carry the highest premiums — often 0.25% to 0.50% above the base rate — and may require an upfront, non-refundable fee. Extended locks are a specialty product and not all lenders offer them.

The general rule is straightforward: the longer the lock period, the higher the rate or fee. Lenders charge more for longer locks because they bear greater risk that market rates will move against them during the extended commitment. When comparing quotes, always ask for the rate at each available lock duration so you can make an informed choice. Our rate comparison tool can help you see how different lenders price their lock options.

Float-Down Options

A float-down option is an add-on feature that lets you reduce your locked rate if market rates fall before closing. It addresses the biggest drawback of a standard rate lock: the possibility that you lock in at 7.00% and rates drop to 6.75% the following week.

Here is how a typical float-down works: you lock your rate as usual, but you pay an additional fee — commonly 0.25% to 0.50% of the loan amount — for the option to adjust your rate downward one time before closing. The adjustment is usually subject to conditions, such as requiring that market rates have dropped by at least 0.25% from your locked rate.

Float-down options are most valuable in volatile or declining rate environments. If you believe rates may fall but want protection in case they rise instead, a float-down gives you the best of both scenarios. However, the upfront cost means you are paying for insurance you may never use. If rates hold steady or increase, the fee is simply an added expense.

Not every lender offers float-down options, and the terms vary widely. Before committing, ask your lender these specific questions: What is the fee? How far must rates drop before you can exercise the option? Can you exercise it at any time or only once during the lock period? Is the fee refundable if you do not use it? Understanding these details helps you evaluate whether the cost is justified for your situation.

When to Lock Your Rate

Deciding when to lock your rate is one of the most consequential financial decisions you will make during the home-buying process. There is no universally perfect time, but several strategies can guide your decision.

• Lock after offer acceptance: Most financial advisors recommend locking your rate as soon as your purchase offer is accepted and you have a clear closing timeline. At this point, you have a defined target date and can choose the appropriate lock duration. Waiting beyond this point exposes you to unnecessary risk.
• Watch economic indicators: Major economic reports — the monthly jobs report, Consumer Price Index (CPI), and Federal Reserve meeting announcements — can cause rates to swing in either direction. If a key report is scheduled and you believe it may push rates higher, locking before the release date can protect you. Learn more about how these forces work in our guide on how the Federal Reserve affects mortgage rates.
• Lock when you are comfortable with the rate: Trying to time the absolute bottom of a rate cycle is nearly impossible, even for professional traders. If the current rate fits your budget and you are satisfied with your monthly payment, that is a strong signal to lock. Waiting for a marginally lower rate introduces the risk of rates moving against you.
• Consider your risk tolerance: If the difference between your current quoted rate and a slightly lower rate would meaningfully change your financial picture, it may be worth waiting. But if you are already at the edge of what you can afford, locking immediately removes a significant variable from the equation.
• Factor in closing timeline: Match your lock period to your realistic closing date, plus a buffer of at least five to seven days. Rushing to close before a lock expires can lead to costly mistakes or the need for an extension, which typically adds 0.125% to 0.25% to your rate.

You can check current mortgage rates on our home page to see where the market stands right now before making your decision.

Risks of Waiting to Lock

Floating your rate — that is, choosing not to lock and hoping rates will fall — is a gamble that does not always pay off. While the potential reward is a lower rate, the risks are significant and asymmetric.

• Rates can spike quickly: Mortgage rates can rise by 0.25% to 0.50% in a single week following an unexpected inflation report, geopolitical event, or Federal Reserve policy shift. On a $400,000 loan, a 0.50% rate increase adds roughly $120 per month to your payment and over $43,000 in total interest over 30 years.
• Budget uncertainty: Without a locked rate, your projected monthly payment is a moving target. This makes it harder to plan your finances, compare homes in different price ranges, and make confident purchasing decisions.
• Emotional pressure: Watching rates fluctuate daily while you are in the middle of the largest financial transaction of your life creates stress. This emotional pressure can lead to hasty decisions — either locking in a panic at a poor time or continuing to wait and missing an advantageous rate.
• Potential qualification issues: If rates rise enough, your debt-to-income ratio may change, and you could no longer qualify for the same loan amount. In extreme cases, this can derail your purchase entirely.

The fundamental insight is this: you cannot reliably predict short-term rate movements. Even professional economists and bond traders frequently get rate forecasts wrong. For most borrowers, the certainty of a locked rate outweighs the speculative upside of floating. If you want to understand the broader forces at play, consider paying down discount points as an alternative strategy for lowering your rate. Our guide on how mortgage points work explains when that approach makes sense.

Key Takeaways

• A rate lock guarantees your interest rate for a specific period, protecting you from market volatility during the closing process.
• Standard lock periods are 30, 45, and 60 days. Longer locks cost more but provide greater protection against delays.
• A 45-day lock is the most common choice for purchase transactions, offering a good balance of cost and timeline flexibility.
• Float-down options let you benefit from falling rates after locking, but they come with an upfront fee that may not be worth the cost in stable rate environments.
• Lock your rate once your offer is accepted and you are comfortable with the quoted rate. Trying to time the absolute bottom is rarely worth the risk.
• Floating your rate exposes you to potentially significant cost increases and budget uncertainty. For most borrowers, locking early is the safer strategy.
• Always ask your lender about lock extension policies and fees before you lock, so there are no surprises if your closing is delayed.

Frequently Asked Questions

What happens if my rate lock expires before closing?

If your rate lock expires before you close, you have two options. You can request a lock extension from your lender, which typically costs 0.125% to 0.375% of the loan amount depending on the length of the extension. Alternatively, your rate will revert to the current market rate at the time of closing, which could be higher or lower than your original lock. To avoid this situation, choose a lock period that gives you a buffer beyond your expected closing date, and stay in close communication with your lender about any processing delays.

Can I break a rate lock if rates drop significantly?

Generally, no. A rate lock is a binding agreement, and most lenders will not let you renegotiate the locked rate downward. This is why float-down options exist — they give you a contractual right to adjust your rate if the market moves favorably. Some lenders may allow you to break a lock, but doing so often involves restarting the application process, paying penalties, or switching to a different loan product. If you are concerned about rates dropping after you lock, ask about float-down options before committing to a standard lock.

Does locking my rate cost money?

For standard lock periods of 30 to 45 days, most lenders do not charge a separate fee — the cost is built into the quoted rate. Longer lock periods carry higher rates to compensate the lender for the extended commitment. Float-down options, lock extensions, and extended locks beyond 60 days typically involve explicit fees ranging from 0.125% to 0.50% of the loan amount. Always ask your lender to itemize any lock-related costs in your Loan Estimate so you can compare offers on equal terms.

Should I lock my rate during a refinance?

Yes, rate locks apply to refinance transactions just as they do to purchase mortgages. Because refinances often have more flexible timelines, you may be able to use a shorter lock period — such as 30 days — which carries a lower cost. However, if your refinance involves a cash-out component or if your property requires a complex appraisal, a 45- or 60-day lock may be more appropriate. The same principles apply: lock when you are satisfied with the rate, choose a lock period that matches your realistic closing timeline, and ask about float-down options if you believe rates may continue to decline.