Duane Buziak

Mortgage Maestro | NMLS #1110647 | Coast2Coast Mortgage LLC

Licensed mortgage broker serving Virginia, Florida, Tennessee, Georgia, Washington DC, North Carolina, South Carolina, and Maryland, specializing in VA home loans and first-time homebuyer programs.

A mortgage rate lock is a written commitment to hold your quoted interest rate and pricing for a set number of days while your loan closes, so market moves after the lock don’t change your rate. What most explainers skip is that the lock only protects you as far as its length, extension terms, and written confirmation allow. A lock that expires a week before closing can cost more than the rate move it was meant to block.

This mortgage rate lock explained guide covers how locks work, what they cost, how to size one, what a float-down does, and how to compare lock terms, with a worked dollar example. It is general education, not a rate quote.

By Duane Buziak, NMLS #1110647

How a Rate Lock Works From Application to Closing

A few terms first. The lock period is the number of days the rate is held, commonly 30, 45, or 60 days as of 2026, though options vary by provider and loan program. The lock expiration is the date that period ends. A quoted rate is only an estimate of where pricing sits today. A locked rate is tied to a specific loan program, loan amount, property, and occupancy type (primary home, second home, or investment). Change any of those and the lock may no longer apply.

The usual sequence runs like this:

1. You apply and receive a Loan Estimate, the standardized three-page form that lists your rate, payment, and closing costs.
2. Once you have a signed purchase contract, you request a lock on a specific program and loan amount.
3. Underwriting reviews income, assets, and credit, and the appraisal is ordered.
4. The file reaches Clear to Close, meaning the conditions are satisfied.
5. You receive the Closing Disclosure at least three business days before closing, and you compare it to your Loan Estimate.

The CFPB explains what a rate lock is and walks through the Loan Estimate form line by line, so you can verify each term yourself.

The most common misconception is that a Loan Estimate is a lock. It is not. A Loan Estimate can show a rate that was never locked, and that rate can change before you lock. A lock exists only when you have asked for it and it has been confirmed with your broker, and that confirmation should be in writing, showing the rate, points, lock date, and expiration date.

Timing matters here. A soft credit pull mortgage pre-approval lets you see realistic numbers before a hard inquiry is placed. The lock is a separate step, and it generally comes after you have a property under contract, because the lock attaches to a specific address and loan amount.

Lock Length, Lock Costs, and When Extensions Apply

Longer locks generally carry more cost. The cost shows up either as a slightly higher interest rate or as extra points paid at closing. Some providers include shorter lock periods without a separate fee. As of 2026, pricing varies by lender, investor, and program, so treat any number you see in an article as a pattern, not a quote.

Matching lock length to your transaction

• Resale purchase: a standard closing timeline often fits a 30 to 45 day lock. Add cushion if the appraisal market is slow or your contract has a financing contingency near its deadline.
• New construction: completion dates slip. Builders often need longer locks, or a separate extended-lock or float-down structure. Ask for this early, because standard locks may not reach the completion date.
• Refinance: there is no contract deadline, so 30 days is often workable if your appraisal and payoff steps move quickly.

Extensions

If closing slips past expiration, an extension typically costs a per-day or per-period charge. Appraisal delays, open underwriting conditions, and title problems are the usual causes. For illustration only, suppose a 15-day extension costs 0.125% of a $400,000 loan. That is $400,000 × 0.00125 = $500. A delay you can’t control becomes a real bill, and the closing table is a bad time to meet it for the first time.

What can void a lock

A lock is not a guarantee of approval. It can be invalidated or repriced if the loan amount changes, your credit profile shifts materially, the property type changes (say, from a single-family home to a condo with a problem project), or you switch programs. Locking the rate protects the price. It does not lock in the underwriting decision.

Float-Down Options and What Happens If Rates Fall After You Lock

A float-down is an option, usually paid for or priced into the lock, that lets you take a lower market rate once if rates drop by a specified amount before closing. The terms vary widely: the minimum drop required, the fee, whether it can be used only once, and the window in which you can exercise it. All of it must be read in the lock agreement, because nothing about a float-down is standard.

If rates fall after you lock, you generally have three paths:

• Stay locked. You keep the agreed rate and accept that the market moved in your favor without you.
• Use a float-down, if you have one. The new rate applies only if the drop meets the agreement’s threshold.
• Ask to relock under the provider’s policy. This may carry a cost, a waiting period, or a requirement that rates have fallen by a minimum amount. Some investors do not permit it at all.

No one can promise which path will work for your loan, and a rate drop that looks large in the news may not clear the threshold in your agreement.

The related misconception is that you can freely cancel a lock and re-lock lower. Policies differ by provider and by the investor who buys the loan, and many treat a lock as a binding commitment on both sides. Ask about the relock policy before you lock, not after rates move.

For market context, Freddie Mac’s Primary Mortgage Market Survey publishes weekly national average rates. It shows direction, not what any individual provider will offer you.

Worked Example: What a 45-Day Lock Is Worth in Dollars

All rates and fees below are illustrative, not current quotes. Suppose a $400,000 loan on a 30-year fixed term. You lock at 6.50%. Without a lock, the rate rises 0.25% to 6.75% before closing.

Monthly principal and interest comes from the standard amortization formula, M = L × r ÷ (1 − (1 + r)⁻ⁿ), where r is the monthly rate and n is 360 payments:

• At 6.50% (r = 0.065 ÷ 12): about $2,528.27 per month.
• At 6.75% (r = 0.0675 ÷ 12): about $2,594.39 per month.
• Difference: $66.12 per month, or about $793 per year. Held for the full 30 years, that is roughly $23,800.

Now the extension math. Using the illustrative $500 for a 15-day extension, compare it with the one-year cost of the rate rise, $793. If a delay would otherwise let you lose the lock and reprice up 0.25%, paying $500 to extend is cheaper than the move. Also suppose a 60-day lock priced $250 higher than a 45-day lock at the outset. If there is better than about a 50% chance you’ll need the extra 15 days, buying the longer lock up front costs less than extending later ($250 versus $500). If your closing is simple and the date is firm, the 45-day lock wins.

The full monthly picture for a $500,000 purchase with 20% down (loan $400,000) follows. The tax figure is an assumed effective rate of 0.85% for illustration. It is not Wake County’s published rate. Look up the current rate and as-of date on the Wake County, NC tax administration page and replace it before using this worksheet for a real decision.

If you put down less than 20%, conventional PMI would be added. Under the Homeowners Protection Act, you can request removal when your balance reaches 80% of the original value, and it ends automatically at 78%. On this $500,000 home, that is a balance of $400,000 and $390,000 respectively. The CFPB explains how PMI cancellation works.

Comparing Lock Terms Across Providers: Comparison Table

Most borrowers compare rates and ignore lock terms. Two quotes at the same rate can differ in how long the lock lasts, what an extension costs, and whether a float-down exists. Below is a factual framework. I have not quoted any provider’s advertised rates, and where I can’t state a term as verified, the cell says to confirm.

The structural difference is simple. A single-company provider shows you its own rate sheet. Duane Buziak, as an independent broker, compares lock pricing across wholesale sources, so you can see how a 45-day lock prices with one investor against another, not just one provider’s version. That is the idea behind “Don’t Guess Your Rate. Shop It.” Lock flexibility is part of what you are shopping.

Questions to ask before you lock

• Who actually holds the lock, and under what investor?
• Is the lock confirmation in writing, with the expiration date shown?
• What is the extension charge per day or per period?
• Is a float-down available, and what drop triggers it?
• What happens to the lock if my loan amount or program changes?

Common Rate Lock Mistakes and Frequently Asked Questions

• Locking before a signed purchase contract. The lock attaches to a specific property, so an early lock can expire before you have a home.
• Choosing a lock shorter than the closing timeline. Count from the lock date to closing, then add cushion.
• Ignoring extension costs. Know the per-day charge before delays happen.
• Assuming a lock covers a change of program. Moving from conventional to FHA, for example, generally means new pricing.
• Not getting the lock in writing. A verbal “you’re locked” is not a confirmation.

How long does a mortgage rate lock last?

A mortgage rate lock commonly lasts 30, 45, or 60 days as of 2026. Some providers offer shorter or longer periods, often at different pricing. The right length is your expected closing date plus a cushion for delays. Confirm the exact expiration date in your written lock confirmation.

Does locking a rate cost money?

Sometimes. Shorter locks are often included without a separate fee, while longer locks may carry a higher rate or added points. Pricing varies by lender and program. Ask for the cost of each lock length in writing before you choose one.

Can I lock a rate without a hard credit pull?

You can get a mortgage pre approval without hard pull through a soft inquiry, which lets you gauge pricing and options. A lock itself usually requires a loan application tied to a property. Ask your broker exactly when a hard inquiry would occur in the process.

What happens if my lock expires?

If your lock expires before closing, you generally either pay for an extension or reprice at current market rates. If rates rose, you pay more. If they fell, you may benefit. Extension fees and repricing rules vary, so ask for them before you lock.

Can I lock before I find a house?

Generally no. A lock is tied to a specific property, loan amount, and program, so most providers require a property under contract. Some offer special structures for new construction. Before that point, a no credit hit mortgage application step, such as a soft-pull pre-approval, shows where pricing stands.

What is a float-down?

A float-down is an option that lets you take a lower market rate once if rates drop by a set amount before closing. It is usually paid for or priced into the lock. The minimum drop, fee, and window vary, so read the lock agreement carefully.

Can a rate lock be extended?

Yes, usually for a per-day or per-period charge. Extensions are typically needed when appraisals, underwriting conditions, or title issues delay closing. The fee structure varies by provider and investor, so ask for the exact cost before you lock, not after a delay occurs.

Does a rate lock guarantee loan approval?

No. A lock protects the rate and pricing only. Approval still depends on underwriting your income, assets, credit, and the appraised property. Changes to your loan amount, credit profile, property, or program can also change or void the lock.

When should I lock my mortgage rate?

Most buyers lock after signing a purchase contract, when the property, loan amount, and program are fixed. Locking earlier risks expiration, while waiting leaves you exposed to rate movement. Market direction is unpredictable, so choose based on your budget tolerance, not a forecast.

Do refinance rate locks work the same way?

Mostly yes. The lock holds your rate for a set period while appraisal, underwriting, and the payoff process finish. Refinances have no purchase contract deadline, but a delay still costs you if the lock expires. The same extension and relock questions apply.

What a Lock Actually Protects, and Your Next Step

A lock shields you from rate movement only as well as its length, extension terms, and written confirmation allow. A 45-day lock with a clear $500 extension charge and a signed confirmation beats a cheaper-looking lock that expires before your appraisal comes back. Before you commit to any lock, put the five questions above to every provider and compare the answers, not just the rates.

For your next step, read our guide on comparing mortgage lenders, then ask Duane Buziak at Shop Mortgage Rates for a side-by-side lock comparison across lock lengths, extension charges, and float-down terms. Your dream home is within reach: discover how much you could save with personalized mortgage rates tailored to your unique situation. Securely pre-qualify in minutes with no impact to your credit score and compare competitive offers from trusted lenders who are ready to help you save.