A rate lock freezes your interest rate for a set window — typically 15, 30, 45, or 60 days — while your loan moves through underwriting and to the closing table. Without a lock, your rate floats with the market until you close, for better or worse.

Locks aren’t free in the sense that pricing tightens as the window lengthens: a 15-day lock is generally priced better than a 60-day lock, because the lender is carrying less market risk. The right length matches your actual timeline — locking too early on a slow purchase risks an extension fee; locking too late leaves you exposed if rates move against you mid-underwrite.

Some lenders offer a float-down option, letting you capture a lower rate if the market improves before closing, usually for a fee or built into slightly wider pricing upfront. We’ll walk through your contract timeline and recommend a lock window before you’re mid-transaction and deciding under pressure.