Rates and Costs
What If Rates Drop After You Lock Your Mortgage Rate?
If rates fall meaningfully after you lock, many lenders offer a one-time float-down that lets you capture part of the improvement before closing, and if they do not, refinancing later remains available once the savings outweigh the costs.
Key takeaways
- A lock protects you from increases; a float-down is the separate feature that lets you benefit from decreases.
- Float-downs usually require a minimum improvement and can only be exercised once.
- Ask about float-down terms at the time you lock, not after rates move.
- A later refinance is the fallback, and it only makes sense when the monthly savings recover the costs within your expected time in the home.
What a lock actually does
A rate lock is the lender committing to hold your rate for a set number of days regardless of market movement. It exists to protect the transaction, and it works: if rates spike two weeks before your Gilbert closing, you are unaffected. The trade-off is symmetry — locking gives up the upside as well as the downside.
Float-down provisions
Many lenders offer a float-down, either built in or for a fee. The common shape is a required minimum improvement in market pricing, a single use, and a deadline before closing documents are drawn. Terms vary widely, so the useful moment to ask is when you lock, so you know in advance what threshold matters.
When breaking a lock makes sense
Occasionally the market moves enough that starting over with a different lender genuinely wins. Weigh it carefully: you restart underwriting, order a new appraisal, risk your contract closing date, and may forfeit fees already paid. In a Phoenix contract with a firm close-of-escrow date and earnest money at stake, that risk is often larger than the interest saved.
The refinance fallback
You are not locked in for thirty years. If rates fall after you close, a refinance recovers most of the difference. The test is simple: divide total refinance costs by the monthly savings to get your break-even in months, and compare that to how long you plan to keep the home. Under three years is generally compelling. Over five deserves scrutiny. The refinance break-even calculator on this site runs it for you.
Frequently Asked Questions
- Can I change my rate after locking?
- Only through a float-down provision if your lender offers one, or by restarting with another lender, which carries real cost and timeline risk.
- How long should I lock my rate?
- Long enough to cover your realistic closing date with a buffer. Resale purchases in the Phoenix metro commonly use 30 to 45 days; new construction needs extended locks.
- Is a float-down free?
- Sometimes it is included, and sometimes it costs a fee or slightly higher initial pricing. Ask for the specific terms before you lock.
The information on this website is provided for general education only and does not constitute financial, tax or legal advice. Loan programs, guidelines and availability are subject to change and to borrower and property qualification.