Rate lock fees, extensions, and float-downs: what the lock really costs
A rate lock is a promise with an expiry date: the lender commits to an interest rate and points for your loan, provided you close within the lock period and nothing in your application changes. Locks are where refinance pricing gets time-sensitive, because the same rate can carry different costs depending on how long the promise lasts, and because running past the expiry can add charges the Loan Estimate never printed. CFPB publishes the consumer frame for locks, and this guide builds on it: how lock periods are priced, what extensions and float-downs are structurally, and the handful of questions that protect you before the clock starts.
What a lock is, and how long it runs
In CFPB's definition, a rate lock means the rate is not expected to change between the offer and closing, as long as you close within the specified timeframe and there are no changes to your application. CFPB notes rate locks are typically available for 30, 45, or 60 days, and sometimes longer. The first page of your Loan Estimate shows whether your rate is locked and, if so, the date and time the lock expires, alongside the date the other closing cost estimates expire.
The conditions matter as much as the date. CFPB lists events that can change a locked rate even inside the period: the home appraises higher or lower than expected, you change the loan type or down payment, your credit score changes, or your income cannot be verified. A lock is a promise about the market, not about your file. If your file changes, the pricing built on it can be reopened.
What a lock costs, and where it shows
Some lenders charge for the lock itself and some treat the lock period as part of pricing: a longer promise generally costs more than a short one, either as an explicit fee or as a slightly worse rate or points for the same loan. CFPB's Loan Estimate guide lists rate-lock fees among the common origination charges in Section A, which is where any explicit lock fee belongs on your disclosure. The guide's standing advice applies with force here: it is the total of Section A that matters, line by line, across lenders.
What the Loan Estimate will not show you is the price of time beyond the lock. CFPB states this consumer tip directly: your Loan Estimate will not show the price for an extension or for the rate lock timeframe, so ask your lender. That means the two numbers most likely to surprise you, the cost of a longer lock and the cost of extending an expiring one, exist only in the answer to a question you have to ask before you lock. Ask it in writing.
Extensions: the price of running late
Closings run late for ordinary reasons: appraisal scheduling, title problems, underwriting conditions, a payoff statement that expires. If your loan is not ready to fund before the lock expires, the lender can usually extend the lock, and CFPB warns it may be expensive to extend if your transaction needs more time. Extension pricing is set by each lender's policy and by market movement since you locked, so this site publishes no figures for it. The structure, though, is askable in advance: how long an extension runs, what it costs, and whether it is quoted as a fee, as points, or as a rate change.
The cheapest extension is the one you never need. Match the lock period to a realistic closing timeline when you lock, not the optimistic one: if the appraisal and title work in your area are slow, a 45 or 60 day lock can cost less in total than a 30 day lock plus an extension. Ask how many days the lender needs from lock to funding on a file like yours, add margin for the appraisal, and choose the period that covers it.
Float-downs: paying for a second chance
A float-down is an option attached to some locks: you lock today's rate, and if rates improve before closing, you may exercise the option to take the better pricing once, under the option's terms. Structures vary, and CFPB publishes no standard form for them, so treat every description as a prompt for questions rather than a definition. Typical structures charge for the option upfront or build its cost into the rate, allow a single exercise, set a deadline by which it must be exercised, and define how much improvement is needed before it can trigger.
A float-down is therefore an insurance product with rules, not a standing promise to chase the market down. Before paying for one, ask: what does the option cost, how many times can it be exercised, by what date, how large an improvement triggers it, and does exercising it extend or restart any clock? Compare the cost against simply taking the standard lock, using the same discipline as discount points: an upfront cost divided by a benefit that only arrives if conditions cooperate, inside a stay you can actually predict.
The lock and your break-even
Everything a lock costs belongs in the same ledger as the rest of the refinance. An explicit lock fee, an extension charge, or a float-down fee is a true closing cost, paid once and never returned, so it joins the total in Section J's cost picture and in your break-even calculation. A refinance that broke even in month 19 before an extension does not break even in month 19 after one.
Run the sequence in this order: get the lock terms and the extension price in writing, choose a period that fits your timeline, then run the calculator with the all-in closing costs, and only then judge the loan against your stay horizon. The break-even guide covers that final test. A lock protects a rate; it does not make a refinance worth doing, and CFPB's other warning is worth keeping in view: a lock can also lock you out of a lower rate if rates fall, which is a market outcome, not a fee, and one no calculator can price in advance.
Worked example
Stated example: a $400,000 balance, 27 years left on the current loan, a new 30-year term, $6,000 of closing costs, and a planned stay of seven years. Before locking this refinance, the borrower asks two written questions: what a 45-day lock costs compared with 30 days, and what a one-week extension would cost if the appraisal runs late. If an extension charge is later added, it joins the $6,000, the break-even month moves out, and the calculator is re-run with the higher total before the borrower decides the loan still clears the seven-year stay comfortably.
The trap most people miss
The trap is discovering the extension price after the lock expires. The Loan Estimate does not print it, the disclosure rules do not require it there, and at expiry you have no leverage. The price of time must be asked for before the clock starts.
Checklist
- Confirm on page 1 of the Loan Estimate whether the rate is locked and the exact expiry date and time.
- Ask, in writing, what the lock period costs and what an extension costs, before locking.
- Choose a lock period that covers a realistic appraisal and title timeline, not the fastest case.
- If a float-down is offered, get its cost, exercise limit, deadline, and trigger in writing.
- Add any lock, extension, or float-down charge into total closing costs and re-run the break-even.
Common questions
How long does a rate lock last?
CFPB says rate locks are typically available for 30, 45, or 60 days, and sometimes longer. Page 1 of your Loan Estimate shows whether your rate is locked and the date and time the lock expires.
Does the Loan Estimate show what an extension costs?
No. CFPB states directly that your Loan Estimate will not show the price for an extension or for the lock timeframe. Ask the lender before you lock, and get the answer in writing.
Can my locked rate change before closing?
Yes, if your application changes. CFPB lists examples: the appraisal comes in higher or lower than expected, you change loan type or down payment, your credit score changes, or your income cannot be verified. The lock holds against market movement, not file changes.
What is a float-down?
An option offered with some locks that lets you take improved pricing once if rates fall before closing, under the option's own terms. Costs and rules vary by lender and are not standardized, so ask about the fee, the exercise limit, the deadline, and the trigger before paying for one.
Do lock fees count toward break-even?
Yes. Lock, extension, and float-down charges are true closing costs paid once and never refunded, so they belong in the total your monthly saving has to repay. Re-run the break-even whenever one is added.
Sources and verification
- Consumer Financial Protection Bureau, What is a rate lock?: consumerfinance.gov Ask CFPB: lock definition, typical 30, 45, or 60 day periods, extension cost warning, and the tip that the Loan Estimate shows no extension price. Checked October 4, 2026.
- Consumer Financial Protection Bureau, Loan Estimate explainer: consumerfinance.gov page-by-page guide to the Loan Estimate: closing cost categories, Section A origination charges, third-party service sections, and the appraisal copy right. Checked October 4, 2026.
Educational explanation, not a quote. Your lock period, extension terms, and any float-down rules are set by your lender in writing on your lock agreement, which governs your transaction.