Rate Locks: When to Lock, When to Float, and How to Protect Yourself
Interest rates can move fast. One week you are looking at 6.5%, the next it is 6.75%. A rate lock protects you from those swings — but timing it right matters. This guide explains how rate locks work, the different options available, and how to make a smart decision about when to pull the trigger.
What Is a Rate Lock, Exactly?
A rate lock is a commitment from the lender: they will honor a specific interest rate for a specific number of days, regardless of what happens in the broader market. Think of it as a price guarantee with an expiration date.
When you lock your rate, three things are set:
Important: A rate lock protects you from rate increases, but it also means you will not benefit from rate decreases (unless you have a float-down option). It is a two-way commitment: you get certainty, but you give up the chance of a better rate.
Typical Lock Periods and What They Cost
Longer lock periods give you more time, but they may come with a slightly higher rate. Here is what to expect.
30 Days
No additional cost (standard)Best for: Straightforward purchases where closing is on track. Most common for purchases with a signed contract.
Tightest timeline. Works well if everything is moving smoothly and you do not expect delays.
45 Days
Usually no additional cost or minimal rate bumpBest for: Purchases with a reasonable closing timeline. Gives a small cushion for inspections, appraisal delays, or document back-and-forth.
The sweet spot for most buyers. Enough time for typical delays without a significant rate premium.
60 Days
May add 0.125% to rate (varies by lender)Best for: New construction or purchases where closing could be delayed. Also useful in competitive markets where you need flexibility.
Worth the slight premium if your closing timeline has uncertainty. Cheaper than an extension if the 30-day lock runs out.
90+ Days
Typically adds 0.25-0.375% to rateBest for: New construction with longer build timelines. Not typical for standard resale purchases.
The rate premium is noticeable. Make sure the certainty is worth the cost, or ask about extended lock programs designed for new construction.
Lock vs. Float: Two Different Strategies
"Floating" means you have not locked your rate yet — you are letting it move with the market while you wait for a better number. Both locking and floating have trade-offs.
Lock Strategy
- Protection from rate increases
- Monthly payment certainty for budgeting
- Peace of mind during the closing process
- Eliminates market-watching stress
- Required before your loan can enter final processing
Downside: If rates drop significantly after you lock, you are stuck at the higher rate (unless you have a float-down option).
Float Strategy
- Opportunity to capture lower rates if market drops
- Flexibility if closing timeline is uncertain
- No commitment until you are ready
- Can monitor economic data and rate trends
- Makes sense in a clearly declining rate environment
Downside: If rates spike, your monthly payment goes up — and there is no guarantee rates will come back down before you need to close.
When to Lock: Situations That Favor Locking Early
Rates have been rising steadily
In an upward trend, waiting usually means a higher rate. Lock to protect yourself from further increases.
You have a signed purchase contract with a firm closing date
Once you know your timeline, there is less reason to float. Lock in certainty so you can focus on the rest of the process.
The current rate fits your budget
If today's rate gives you a monthly payment you are comfortable with, lock it. Chasing a slightly better rate is not worth the risk of a significantly worse one.
Major economic events are on the horizon
Federal Reserve meetings, jobs reports, and inflation data can move rates in either direction. If you are nervous about volatility, locking removes the uncertainty.
You are risk-averse about your monthly payment
If a 0.25% rate increase would stretch your budget or cause stress, lock. The peace of mind has real value.
When Floating Might Make Sense
Rates have been dropping consistently
If there is clear downward momentum, floating for a few more days or weeks could save you money. But set a target rate and lock when you hit it — do not get greedy.
Your closing is more than 60 days away
A lot can change in 60+ days. If you lock too early, you might need an expensive extension. Sometimes it makes sense to float until you are within a typical lock window.
You are working with a loan officer who monitors rates daily
An experienced loan officer can alert you to favorable lock opportunities and help you time the decision. This is not something to do alone.
Float-Down Options: The Best of Both Worlds?
A float-down option lets you lock your rate now but take advantage of a lower rate if the market drops before closing. It sounds like a no-brainer, but there are rules and costs to understand.
How it works
You lock your rate as usual. If rates drop by a certain amount (often 0.25% or more) before a specified date, you can request the lower rate. Some float-downs are automatic; others require you to exercise the option.
What it typically costs
Some lenders offer float-down at no extra charge. Others charge a small fee (0.125-0.25% of the loan amount) or build the cost into a slightly higher initial rate. Ask your loan officer what the specific terms are.
When it makes sense
Float-downs are most valuable in a declining rate environment where you want protection against rates going up but do not want to miss out if they continue dropping. They offer insurance in both directions.
Limitations to watch for
Float-down options usually have a minimum rate drop required (you cannot float down for a 0.05% change), a specific exercise window, and the new rate may not be as low as the full market rate. Read the fine print.
Ask your loan officer: "Do you offer a float-down option? What are the terms, cost, and minimum rate drop required?" Not all lenders offer this, and the specifics vary widely. It is worth asking about as part of your rate lock conversation.
What Happens If Your Rate Lock Expires
Life happens. Appraisals come in late, sellers need more time, documents take longer than expected. If your closing gets pushed past your lock expiration, here are your options.
Extend the lock
0.125-0.25% of loan amount per extensionMost lenders allow you to extend your lock for a fee, typically 0.125-0.25% of the loan amount per 7-15 day extension. If rates have gone up since you locked, this is usually the best option — the extension fee is less than the rate increase.
Re-lock at current rates
Depends on current market ratesIf rates have dropped since your original lock, the lender may let you re-lock at the new lower rate. If rates have gone up, you will be paying the higher rate. This is a gamble that depends on market movement.
Worst-worse-case policy
Varies by lender policySome lenders have a 'worst case' policy where they give you the worse of the expired rate or the current rate on re-lock. Others may offer the better of the two. Ask about this policy before you lock — not after it expires.
How to Avoid Lock Expiration Issues
- Choose a lock period with a buffer — if your closing is 35 days away, lock for 45 days, not 30
- Stay on top of document requests and respond to your loan officer quickly
- Communicate proactively if you sense the closing timeline is slipping
- Ask your loan officer about their lock extension policy before you lock, not after
- If you are buying new construction, ask about extended lock programs designed for longer timelines
What Actually Moves Mortgage Rates
Understanding what drives rate movement helps you make smarter lock decisions. Mortgage rates are influenced by several macroeconomic factors — not just the Federal Reserve.
The 10-Year Treasury Yield
Mortgage rates tend to track the 10-year Treasury yield. When the yield rises, mortgage rates usually follow. This is the single most important daily indicator.
Federal Reserve Policy
The Fed does not set mortgage rates directly, but their decisions on the federal funds rate and bond purchases influence the broader rate environment. Fed meetings can cause significant rate volatility.
Inflation Data
Higher inflation tends to push rates up because it erodes the value of fixed-income investments. Key reports include the Consumer Price Index (CPI) and Personal Consumption Expenditures (PCE).
Jobs Reports
Strong employment data can push rates higher (signals a strong economy that may fuel inflation). Weak data can push rates lower. The monthly jobs report is a major rate-moving event.
Global Economic Events
Geopolitical uncertainty, international financial crises, or global recessions can drive investors toward safe-haven assets like Treasury bonds, which tends to push rates down.
Mortgage-Backed Securities Market
Mortgage rates are ultimately set by supply and demand in the mortgage-backed securities (MBS) market. High demand for MBS pushes rates down; low demand pushes them up.
Practical takeaway: You cannot predict where rates will be next month. Even professional economists get it wrong regularly. Focus on whether today's rate works for your budget and your goals — not on trying to time the bottom.
Your Rate Lock Checklist
Before you lock, make sure you have addressed these items.
Rate Lock Mistakes to Avoid
Waiting too long to lock because you are chasing a lower rate
Risk: Rates can spike 0.25-0.50% in a single week based on economic data. The rate you turned down Monday might look great by Friday.
Locking too early when your closing date is far out
Risk: If you lock for 30 days but your closing is 50 days away, you will need an expensive extension. Match your lock period to your realistic timeline.
Not getting the lock confirmation in writing
Risk: Verbal locks are not locks. Get a written confirmation that includes the rate, lock period, expiration date, and any points or credits. Review it carefully.
Forgetting about your lock while waiting to close
Risk: Track your lock expiration date. If closing is approaching the deadline, proactively discuss extension options with your loan officer. Do not discover the problem at closing.
Not asking about the extension policy upfront
Risk: Extension costs and policies vary significantly between lenders. Know the rules before you need them, not when you are scrambling.
Frequently Asked Questions
What is a mortgage rate lock?
A rate lock is an agreement between you and the lender that guarantees a specific interest rate for a set period of time, usually 30 to 60 days. Once locked, your rate will not change even if market rates go up before you close.
Does locking my rate cost anything?
Standard rate locks (30-45 days) are typically included at no extra cost. Longer lock periods (60-90+ days) may come with a slightly higher rate or a fee because the lender takes on more risk holding that rate for a longer time.
Can I lock my rate before I find a house?
Some lenders offer pre-approval rate locks that let you lock before you have a signed purchase contract. Ask a loan officer about eligibility — these programs vary by lender and typically have specific terms and conditions.
What happens if rates drop after I lock?
If you have a standard rate lock, your rate stays at the locked level even if rates drop. However, some lenders offer a float-down option that lets you take advantage of a significant rate decrease. This option often comes with specific rules about the size of the rate drop required.
What if my closing is delayed past my lock expiration?
If your lock expires before closing, you will need to extend the lock (which may cost a fee, typically 0.125-0.25% of the loan amount per extension) or re-lock at the current market rate, which could be higher or lower than your original lock.
Can I switch lenders after locking a rate?
You can, but you will lose your rate lock with the original lender. The new lender will offer you their current rates. Switching after locking is generally only worthwhile if the new lender offers significantly better terms that justify starting over.
Talk Rate Strategy With a Loan Officer
A loan officer in the AMLO network can help you develop a rate lock strategy based on your timeline, risk tolerance, and the current market. No obligation — just informed guidance.
AMLO is an educational platform and does not originate, fund, or service mortgage loans. AMLO is not a lender, broker, or bank. Rate lock terms, costs, float-down options, and extension policies vary by lender and are subject to change. Examples provided are illustrative and do not represent specific loan offers. Information provided is for educational purposes only and does not constitute financial advice. Consult a licensed loan officer for personalized rate lock guidance. Equal Housing Opportunity.