A rate lock is the difference between the payment you budgeted for and a payment that drifts with the market. It is one of the few decisions in the home buying process where a little planning saves real money. Here is the whole playbook, from when to lock to what happens when the date moves.

When to lock your rate

The term: a rate lock is your lender's written guarantee that your rate, and usually your points, stay put for a set number of days tied to your closing.

The meaning: the best time to lock is when you have a signed purchase contract and you are comfortable with the rate, once your application is complete and your credit has been reviewed.

The real-world play: some lenders offer a rate locker program that holds pricing before you have a property under contract, useful when you are shopping and want to protect today's rate while you search. Ask about it early.

Lock periods and timing

The term: standard lock periods run 30, 45, or 60 days, and the length is tied to your expected closing date.

The money: shorter locks typically cost less; longer locks cost more but give you a buffer if closing is delayed. Choose a period that extends at least a few days past your expected closing date.

The real-world consequence: if you are not sure about the closing date, err longer. The extra cost of a longer lock is usually cheaper than the fee on an extension you did not plan for.

Float-down options

The meaning: a float-down option lets you lock at today's rate but request a lower rate if market rates drop during your lock period. It is a protection against locking right before a drop.

The money: the option may add cost upfront or carry a fee, so it only pays when the market actually drops enough to beat that cost. Not all lenders offer it, so ask before you lock.

The real-world play: a free float-down is almost always worth having. A paid one needs the math to work. I help clients decide which side of that line they are on.

Extensions and delays

The meaning: if your lock expires before closing, you can request an extension, usually at a fee based on the number of extra days.

The money: contact your lender well before the expiration date to arrange the extension. Waiting until the last day limits your options and can force a repricing at current market rates, which is the expensive outcome.

The real-world consequence: the moment your closing date moves, tell your loan officer. The cheapest extension is the one requested early.

The smart lock strategy

The meaning: lock once, correctly, the day your contract is solid and your program is decided. Do not chase one more eighth of a point, because waiting can mean missing the bus entirely.

• Lock when you are comfortable with the rate and have a signed contract.
• Choose a lock period longer than your expected closing timeline.
• Ask about float-down options for flexibility.
• Communicate with your lender if your closing timeline changes.
• Refinancing is always an option if rates drop after you close.

The real-world play: buyers in San Antonio and the Texas Hill Country win with this playbook: know the rate, lock the window, and never let a delay go unspoken. I walk every client through it. Make it a great one.