Locking your rate protects you from increases while your loan processes. Here is when to lock, what lock periods cost, and how float-down options work.
Locking your rate protects you from increases while your loan processes. Here is when to lock, what lock periods cost, and how float-down options work.
A mortgage rate lock is a lender guarantee that your interest rate will not change during a specified period — typically 30, 45, or 60 days — while your loan is being processed. Without a rate lock, your rate is subject to market fluctuation from day of application to closing.
Lock when you're comfortable with the rate and have a signed purchase contract. Common strategies:
| Lock Period | Typical Cost | Best For |
|---|---|---|
| 15 days | Free | Refinances near close |
| 30 days | Free | Standard purchases |
| 45 days | 0.125%–0.25% | Complex purchases, new construction |
| 60 days | 0.25%–0.5% | Extended timelines |
| 90–180 days | 0.5%–1.0%+ | New construction, extended timelines |
If your loan doesn't close before the lock expiration, you have options: extend the lock (0.125–0.25% per week typically), re-lock at current market rates (risk: rates may have risen), or close with a short-term lock if almost ready. Work with your lender proactively — flag potential delays at least 5–7 days before expiration.
A float-down option allows you to reduce your locked rate once if market rates drop by a threshold (usually 0.25–0.5%). Cost: typically 0.125–0.25% of loan amount. Worth considering in volatile rate environments where rates might fall, but you need protection against them rising.