Rate lock, explained

What it means

A rate lock is a lender's promise to honor a specific interest rate for a defined window, typically 30 to 60 days, while you finalize your loan or refinance. Once locked, your rate won't rise even if market rates climb before closing. Rate locks are common in mortgage lending but less standard in auto finance. Some auto lenders and credit unions offer short-term rate locks if you're pre-approved, especially during volatile rate environments. If rates drop after you lock, most lenders won't let you float down without starting over.

Why it matters

Interest rates can swing week to week, and a quarter-point increase on a $30,000 loan costs you hundreds over five years. A rate lock gives you certainty while you negotiate the car price, gather paperwork, or wait for your trade-in payoff quote. Without one, the rate you're pre-approved for can evaporate by the time you're ready to sign. If you're refinancing, rate locks let you time the market without rushing the paperwork.

What to do

Ask every lender whether they offer rate locks and how long they last. If you're comparing refi offers across multiple lenders, check current market rates and lock timing with our refinance verdict tool to see whether refinancing saves you enough to justify the urgency.