In short
A rate lock means your interest rate won’t change between the offer and closing, as long as you close within the lock period and your application does not change. The CFPB says locks are typically available for 30, 45 or 60 days, sometimes longer. Your Loan Estimate must say whether the rate is locked and, if so, the date and time the lock ends. If you lock after receiving the Loan Estimate, the lender must send a revised one within three business days.
What a rate lock is
Mortgage rates can change daily, sometimes hourly, the CFPB notes. A lock fixes your rate from the day you lock until closing, under two conditions:
- you close within the specified time frame; and
- there are no changes to your application.
If your rate is not locked, it can change at any time before closing. See mortgage rates explained for what drives the rate you are offered.
Lock periods
The CFPB says rate locks are typically available for:
| Lock period | Notes |
|---|---|
| 30 days | Typical option |
| 45 days | Typical option |
| 60 days | Typical option |
| Longer | Sometimes available |
Lock policies vary by lender. The CFPB suggests making sure the lock is long enough to cover the time until closing. If you worry the period is too short, ask about switching to a longer lock now rather than later. Ask whether a shorter or longer lock is available and at what cost.
What the Loan Estimate must show
Federal rules (Regulation Z) set what the Loan Estimate says about the lock:
- Rate Lock line. Page 1 must state whether the interest rate is locked for a specific period, labeled “Rate Lock” (12 CFR 1026.37(a)(13)).
- End date and time. If the rate is locked, the lender must give the date and time, including the time zone, when the lock period ends.
- Warning. The form must state that the rate, points and lender credits may change unless the rate has been locked.
- Revised estimate after locking. If the rate was not locked when you got the Loan Estimate, the lender must send a revised one no later than three business days after the lock, with the new rate, points, lender credits and other rate-dependent charges (12 CFR 1026.19(e)(3)(iv)(D)).
The CFPB adds that the Loan Estimate does not show how much it costs to extend the lock, what you pay for the specific lock period, or the price of a different period. Ask for those details.
What can still change a locked rate
A lock protects you from market movements, not from changes in your file. The CFPB lists common reasons a locked rate can change:
- you change the kind of loan or the down payment amount (see down payment);
- the appraisal comes in higher or lower than expected;
- your credit score changes, for example after a new loan or a missed payment (see credit score and mortgage);
- the lender cannot document overtime, bonus or other income.
Changes in your loan amount or verified income can also change the rate.
If rates fall: float-down options
The CFPB points out a downside of locking: a lock may keep you from a lower rate if rates fall after you get your offer. Some lock agreements include a float-down option. CFPB rules for lender reporting (Regulation C commentary) mention a rate being reset after a lock “because the borrower exercises a float-down option or the agreement expires”.
Rate lock policies vary by lender, the CFPB says, so ask whether a float-down is offered, what it costs and when it can be used. The CFPB suggests asking: “If I lock my rate, and interest rates go down, what happens?”
If the lock expires
A lock only holds if you close within the specified time frame. The CFPB notes that a lock may be expensive to extend if your transaction needs more time. The Regulation C commentary quoted above also anticipates that a rate may be reset when a lock agreement expires.
Before you lock, ask:
- “What if my closing is delayed and the rate lock expires?”
- “Is a shorter or longer rate lock available, and at what cost?”
- “If I lock my rate, are there any conditions under which my rate could still change?”
Timing your lock with your preapproval and closing date reduces the risk of paying for an extension. For costs at closing, see closing costs explained.
Frequently asked questions
How long does a mortgage rate lock last?
The CFPB says locks are typically available for 30, 45 or 60 days, and sometimes longer. The exact period is in your lock agreement and on page 1 of your Loan Estimate.
Does every lender lock the rate with the Loan Estimate?
No. The CFPB says some lenders lock the rate when they issue the Loan Estimate and some do not. Check the “Rate Lock” line at the top of page 1.
Can a locked rate still go up?
Yes, if your application changes: loan type, down payment, appraisal, credit score or documented income. Market movements alone do not change a locked rate within the lock period.
What is a float-down option?
It is an option, named in CFPB rules, under which a borrower can have a locked rate reset after the lock agreement is signed. Lock policies vary by lender, so ask each lender whether it is offered and what it costs.
What happens if I lock after getting my Loan Estimate?
The lender must send a revised Loan Estimate no later than three business days after the rate is locked, showing the locked rate, points and lender credits.
General information drawn from the official sources cited and dated on this page. It is not legal, tax or financial advice: for your own situation, ask a licensed professional.
More financing guides
- Mortgage Discount Points: How They Work and Tax Rules
- Adjustable-Rate Mortgage (ARM): Index, Margin and Caps
- 15-Year vs 30-Year Mortgage: Payment and Interest Compared
- Jumbo Loans and 2026 Conforming Loan Limits
- Home Equity Loan vs HELOC: Key Differences
- Reverse Mortgage (HECM): Rules and Repayment
- Gift Funds for a Down Payment: Rules and Gift Letter
- Assumable Mortgages: FHA, VA and USDA Rules
- Mortgage preapproval: what lenders check, how long it lasts
- Conventional loans: requirements and 2026 limits
- FHA loans: requirements, 2026 limits and mortgage insurance
- VA loans: eligibility and funding fee
- USDA loans: eligible areas, income limits and fees
- How much down payment do you need to buy a home?
- Private mortgage insurance (PMI): how to remove it
- Credit score and mortgage rates: what lenders look at
- Debt-to-income ratio: the limits mortgage lenders use
- How mortgage rates are set: rate, APR, points and locks
- Escrow accounts for taxes and insurance: your rights
- Refinancing a mortgage: costs, break-even and your rights
Sources
- What's a lock-in or a rate lock on a mortgage? (Consumer Financial Protection Bureau) (consulted October 19, 2026)
- § 1026.37 Content of disclosures for certain mortgage transactions (Loan Estimate) (Consumer Financial Protection Bureau) (consulted October 19, 2026)
- § 1026.19 Certain mortgage and variable-rate transactions (Consumer Financial Protection Bureau) (consulted October 19, 2026)
- Comment for 1003.4 - Compilation of Reportable Data (Consumer Financial Protection Bureau) (consulted October 19, 2026)