Mortgage Rate Locks Explained: 2026 Complete Guide

What Is a Mortgage Rate Lock?

A mortgage rate lock is a lender's written commitment to hold a specific interest rate for you for a defined period of time. Once locked, your rate won't change even if market rates rise before your loan closes — which in a volatile rate environment like 2026, can save you thousands of dollars over the life of your loan.

Rate locks are one of the most misunderstood parts of the mortgage process. Borrowers either don't lock soon enough, lock too early, or don't know what they agreed to. This guide breaks down everything you need to know so you can lock strategically — not accidentally.

How Does a Mortgage Rate Lock Work?

Once you're under contract on a home and your loan application is submitted, your lender will offer you the option to lock your interest rate. The lock agreement specifies:

• The locked rate (e.g., 6.75% on a 30-year fixed)
• The lock period (typically 15, 30, 45, or 60 days)
• Any associated cost (shorter locks are usually free; longer locks may carry a fee or slightly higher rate)
• What happens if the lock expires before closing

If you close before the lock expires, you're protected. If rates drop significantly after you lock, you generally don't benefit — unless you have a float-down option, which we'll cover below.

When Should You Lock Your Mortgage Rate?

This is the question I get most often from Seattle buyers. The honest answer: lock when you're comfortable with the rate and the math works for your purchase. Trying to time interest rates is like trying to time the stock market — even the pros get it wrong.

That said, here are the most common timing strategies:

Lock at Pre-Approval

Some lenders offer pre-approval rate locks, but these are rare and usually short (15–30 days). Unless you're in a very fast-moving market and expect to close quickly, this is generally too early.

Lock When You Go Under Contract

This is the most common approach and what I recommend for most buyers. Once you have an accepted offer, you have a target closing date, which lets you choose the right lock period. A standard 30-day lock usually works for a straightforward purchase in Washington State, where closing timelines typically run 30–45 days.

Float and Watch

Some buyers choose to float — meaning they don't lock immediately and hope rates improve before closing. This is a calculated risk. If rates drop, great. If they rise, you pay more. I only recommend floating if you have a strong risk tolerance and a longer closing timeline.

How Long Should Your Rate Lock Be?

Match your lock period to your expected closing date, plus a small buffer. Here's a general framework for Washington State purchases:

• 15–30 days: Refinances or purchases with all documentation ready and no complications expected
• 30–45 days: Standard purchase transactions — the most common choice
• 45–60 days: Condos (which require HOA document review), new construction with defined timelines, or complex income situations like self-employed borrowers or RSU/stock option income
• 60–90+ days: New construction with uncertain completion dates — these typically require extended lock products with higher pricing

A 30-day lock is typically free or priced into the base rate. A 60-day lock might add 0.125% to 0.25% to your rate, depending on the lender and market conditions.

What Happens If Your Rate Lock Expires?

If your closing is delayed past your lock expiration date, you have a few options:

• Extension: Most lenders will extend your lock for a fee — typically 0.125% to 0.25% of the loan amount per 15-day extension. On a $700,000 Seattle purchase, that's $875 to $1,750 per extension period.
• Renegotiate at current market rates: If rates have dropped since you locked, this could actually work in your favor.
• Float to close: Some lenders allow a short float period after expiration, taking the current market rate at closing.

The key lesson: don't let your lock expire without a plan. Work closely with your lender to identify any potential delays early — appraisal issues, title problems, or HOA document delays are the most common culprits here in King County.

What Is a Float-Down Option?

A float-down option is an add-on to your rate lock that allows you to take a lower rate if market rates drop by a certain amount (usually 0.25% or more) before closing. It's essentially downside protection against rate increases combined with upside if rates fall.

Float-down options typically cost 0.125% to 0.5% of the loan amount upfront. Whether it's worth it depends on rate volatility and how much rates would need to fall to break even. I walk through this math with clients on a case-by-case basis.

Does a Rate Lock Cost Money?

Not always — but it depends on the lock period and your lender. Here's the general breakdown in 2026:

• 30-day lock: Usually free (priced into the rate)
• 45-day lock: Free to +0.125% to the rate
• 60-day lock: Typically +0.125% to +0.25% to the rate
• 90-day lock: +0.375% to +0.5% or higher

These costs are reflected either as a slightly higher interest rate or as points on your Loan Estimate. Always compare lock pricing across lenders — it varies more than most buyers realize.

Rate Lock vs. Rate Float: Which Is Right for You?

There's no universal answer, but here's how I frame it for my Seattle clients: if you'd be upset waking up to a rate 0.25% higher tomorrow, lock today. If you have flexibility in your budget and timeline, floating may give you an opportunity — but it's a gamble, not a strategy.

In a rising rate environment, locking quickly is almost always the right move. In a falling rate environment, floating short-term or using a float-down option may make sense. Either way, the decision should be based on your specific loan amount, timeline, and risk tolerance — not a guess about where the Fed is heading.

Common Rate Lock Mistakes to Avoid

• Locking before you have an accepted offer — your lock may expire before you find a home
• Choosing too short a lock period to save money, then paying more for an extension
• Not confirming your lock in writing — always get a rate lock confirmation document from your lender
• Assuming your rate is locked before you've officially requested it — floating is the default until you say otherwise
• Not asking about float-down options when rates are actively falling

Understanding how mortgage points interact with your locked rate is also worth discussing with your advisor before you commit.

Rate Locks in the Seattle Market: What's Different

Seattle's competitive market creates unique pressure around rate locks. Bidding wars and tight timelines mean you may be writing offers on multiple homes before getting one accepted. This makes it difficult to lock early without risking expiration. My advice: get fully pre-approved, know your rate lock options, and be ready to lock immediately once your offer is accepted.

For condos in Seattle specifically, build in extra time. Condo approvals require HOA document review, which can add 1–2 weeks to your timeline. A 45-day lock is usually the safer choice for Seattle condo purchases.

Ready to Lock? Let's Talk Strategy

Rate lock timing is one of those decisions that looks simple on the surface but has real financial consequences. The right choice depends on your specific loan, your closing timeline, current market conditions, and your comfort with risk.

I've helped hundreds of Washington buyers navigate this decision over 20+ years. If you're under contract or approaching the offer stage, schedule a consultation with me at jdonion.com and we'll build a rate lock strategy that fits your situation — not a one-size-fits-all answer.