Rate Locks Explained: What Happens If Rates Move After You Lock

Locking your rate is one of the most misunderstood parts of the mortgage process. Here's what it actually does and why timing matters.

I'm Lilli, a Senior Loan Officer here at East Coast Mortgage, and rate locks are one of the parts of this process that I explain the most, because most buyers have heard the term but nobody's ever actually walked them through it.

What a rate lock actually does

When you lock your rate, your lender is agreeing to hold that specific rate for you for a set period of time, regardless of what happens in the broader market between now and closing. It's a way of protecting you from movement you can't control while your loan makes its way through processing and underwriting.

Why timing matters so much

A rate lock only lasts for a set window. If your closing gets pushed past that window, you may need an extension, and depending on your lender and the situation, that can come with its own considerations. This is exactly why staying responsive with documents matters so much. The smoother your file moves, the less you have to think about lock timing at all.

What happens if rates move after you lock

This is the part people worry about most, so let's be direct about it. Once you're locked, that's your rate for the loan, regardless of which direction the market moves afterward. If rates drop after you lock, you don't automatically get the lower rate, your lock is what it is. If rates rise after you lock, you're protected, because you already secured your number. It's a trade-off: certainty in exchange for giving up the chance of a lucky swing either way.

So when should you actually lock

This is genuinely a conversation, not a one-size answer, because it depends on where you are in the process, how the market's been moving, and your own comfort with uncertainty. Some buyers want to lock the moment they can, just for the peace of mind. Others want to wait a little longer. Neither instinct is wrong. I'd rather talk it through with you honestly than tell you there's one right move for everyone.

What I'd tell every buyer about this

Don't treat a rate lock like a guessing game you have to win. Treat it like a tool that gives you certainty once you use it. The goal isn't predicting the market perfectly, it's making sure you're not caught off guard by it while you're trying to close on a house.

If you're getting close to locking and want to talk through timing honestly, reach out. This is one of those conversations I'd genuinely rather have with you directly than have you guess alone.

Written by a real loan officer

Lilli Driscoll, NMLS #2485560

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