What Is a Mortgage Rate Lock? California Borrower’s Guide

I’m Michael DiVita — DRE #01372066 | NMLS #241655, DiVita Home Finance (DRE #01818285 | NMLS #323700), Tiburon, CA. I’ve been in California mortgage lending since 2000 and founded DiVita Home Finance in 2007. I’m known as a creative mortgage broker: when a bank says no, I find the lender and the loan structure that can say yes. Call (800) 239-1103.

A mortgage rate lock is a lender’s commitment to hold a specific interest rate and price (points or credits) for a set number of days — usually 30 to 60 — while your loan closes. Lock once you’re in contract and the payment works for you, choose a lock long enough to cover a realistic closing date, and get the lock confirmation in writing. If the lock expires before you close, you’ll typically pay to extend it or re-price at the current market.

Rates move every day, and in a volatile stretch they can move 0.10%–0.25% in a week. In September 2026, for example, Freddie Mac’s 30-year average rose from 6.95% to 7.03% in the week after the Federal Reserve’s rate hike, and daily lender pricing moved more than that. A lock takes that risk off the table while your escrow runs.

What a Rate Lock Does — and Doesn’t — Do

• It protects your rate and price. If market rates rise during the lock, your rate and points stay the same (as long as your loan details don’t change).
• It works both ways. If rates fall, you generally keep the locked rate unless you have a float-down option or re-lock (which usually has a cost or restrictions).
• It’s tied to your loan details. If your credit score, loan amount, down payment, property type, or appraised value changes, the price can change even while you’re locked.
• It isn’t a loan approval. You still need to clear underwriting, the appraisal, and title.

Under federal disclosure rules, your Loan Estimate shows whether your rate is locked and when the lock expires, and after you lock the lender must send a revised Loan Estimate within three business days. Always ask for written lock confirmation.

When to Lock

Most of my clients lock within a day or two of going into contract. The question isn’t “will rates go down?” — nobody knows that, including me. It’s “does this payment work?” If yes, lock. Floating when you already have a deal is a bet with your house payment.

There are exceptions:

• You’re not in contract yet. Most lenders need a property address to lock. Some offer lock-and-shop programs that lock before you find a home, usually at a cost.
• New construction. Builders’ timelines can run months. Extended locks are available from some lenders — price that in when comparing the builder’s preferred lender against an outside lender.
• Refinances. With no purchase deadline, some borrowers float for a better rate. That’s reasonable if you’re watching the market and can live with the risk of rates rising.

Choosing the Lock Length

Match the lock to a realistic closing date, then add a cushion. Longer locks cost more, and the cost varies by lender and market conditions.

Scenario	Typical escrow	Lock I usually suggest
Conventional purchase, clean W-2 file	21–30 days	30 days
FHA or VA purchase	30–45 days	45 days
Jumbo, self-employed, or complex income	30–45 days	45 days
Condo with HOA review, or estate/trust sale	30–45+ days	45–60 days
New construction	Varies	Extended lock — confirm cost in writing

A 30-day lock is usually priced into the rate. A 45- or 60-day lock generally costs a little more, either in a slightly higher rate or a fraction of a point. Paying for a few extra days up front is usually cheaper than an extension later.

What Delays California Closings

In my experience, most lock extensions come from avoidable delays:

• Appraisal turnaround, especially for jumbo loans, rural or acreage properties, and busy seasons.
• Condo documents. HOA questionnaires, budgets, reserve studies, and SB 326 balcony-inspection reports can take time. See SB 326 and condo financing.
• Insurance. In fire-exposed areas, getting a binder — sometimes a FAIR Plan policy plus supplemental coverage — can take longer than buyers expect. See the FAIR Plan wrap policy guide.
• Title issues on trust, estate, or probate sales.
• Late documents. Self-employed borrowers and those with RSU or bonus income should have documents ready before the lock clock starts. See the pre-approval checklist.

If you see the closing date slipping, tell your loan officer immediately. An extension arranged before expiration is almost always cheaper than re-locking after the lock expires.

If Your Lock Expires

You’ll generally have two options: pay for an extension (the fee varies by lender and the number of days), or re-lock at current market pricing — which may be worse than your original rate if rates have risen (many lenders apply “worst-case” pricing to expired locks). Who pays for the extension can depend on why the closing slipped, so ask about it up front.

Float-Down Options

A float-down lets you lower your locked rate once if market rates improve by a set threshold before closing. Some lenders build a float-down into certain programs; others charge for it up front. It’s most useful on long locks in a volatile market. Before paying for one, ask: How much must rates drop to trigger it? Is there a fee to exercise it? What’s the deadline? Then compare that cost with the odds of rates falling meaningfully during your escrow.

Lock Strategy in Today’s Market

With the Fed raising its policy rate to 3.75%–4.00% on September 16, 2026, and the 10-year Treasury trading above 5%, this is not a market where I’d float a purchase in hopes of a drop. My general approach right now:

1. Get fully underwritten before you’re in contract so you can close on time.
2. Lock once you’re in contract, for a period that covers your realistic closing date plus a cushion.
3. Keep the loan easy to refinance — no prepayment penalty, and think twice before paying heavy discount points — so if rates do fall later, you can take advantage.
4. If a seller is offering credits, consider a buydown instead of a price cut.

For background on what moves rates day to day, see why mortgage rates change daily.

Frequently Asked Questions

What is a mortgage rate lock?

It’s a lender’s commitment to hold a specific interest rate and price for a set period, usually 30 to 60 days, while your loan closes. If rates rise, your locked rate is protected as long as your loan details don’t change. If rates fall, you keep the locked rate unless you have a float-down option.

When should I lock my mortgage rate in California?

Most buyers lock within a day or two of going into contract, once the payment works for their budget. Floating when you already have a deal is a bet that rates will fall, and rates can move quickly on economic news.

How long should my rate lock be?

Long enough to cover a realistic closing date plus a cushion: often 30 days for a clean conventional purchase and 45 days for FHA, VA, jumbo, self-employed, or condo files. Longer locks cost more, but usually less than an extension.

What happens if my rate lock expires before closing?

You can usually pay to extend the lock or re-lock at current market pricing, which may be higher. Extension fees vary by lender. Tell your loan officer as soon as you see the closing date slipping, because extending before expiration is typically cheaper.

What is a float-down option?

A float-down lets you lower your locked rate once if market rates drop by a set threshold before closing. Some programs include it and others charge for it. Check the trigger, the cost, and the deadline before paying for one.

Can I lock my rate before finding a home?

Most lenders need a property address to lock. Some offer lock-and-shop programs that let you lock before you’re in contract, usually for a fee or a slightly higher rate. New construction often uses extended locks.

Can my rate change after I lock?

Yes, if your loan details change — for example, a different loan amount, credit score, property type, or appraised value. The lender must send a revised Loan Estimate within three business days after you lock, and it should show the lock expiration date.

Related Resources

• Current Mortgage Rates in California
• Why Mortgage Rates Change Daily
• Mortgage Approval Timeline in California
• Mortgage Buydowns
• California Closing Costs
• Mortgage Pre-Approval Checklist

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