Should you lock your mortgage rate now?
Compare lock timing options, see the real cost of waiting, and walk into your next lender conversation prepared.
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Your rate lock scenarios
Here's what each decision could cost you based on your loan.
Lock now
Safe choiceYour rate is guaranteed. If rates go up, you win. If they drop more than your float-down threshold, you might feel like you missed out.
Wait 15 days
RiskyYou could save money or pay more. The risk is higher with less time before closing because you have fewer chances to time it right.
Lock with float-down
Best protectionYou lock in now but keep the option to take a lower rate if the market drops. The upfront fee pays for this flexibility.
Lock window comparison
Longer lock windows cost more because the lender takes on more risk. Here's how the typical options stack up.
| Lock period | Typical cost | Best for | Watch out for |
|---|---|---|---|
| 15-day lock | Free to 0.125% | Closings within 2 weeks, rate shopping | Delays push you past the window |
| 30-day lock | Free to 0.25% | Most standard purchases | Appraisal or title delays can cause issues |
| 45-day lock | 0.125% to 0.375% | New construction, complex deals | You're paying for time you might not need |
| 60-day lock | 0.25% to 0.5% | Long closings, builder delays | Most expensive option, often unnecessary |
These are typical ranges. Your lender may charge differently. Always ask for the exact cost in dollars, not just percentages, so you can compare apples to apples.
What actually happens in different rate environments
Here are three real-world scenarios to help you think through your decision.
Scenario A: Rates drop after you lock
You lock at 6.875%. Two weeks later, rates drop to 6.5%. Without a float-down, you're stuck with the higher rate. On a $350,000 loan, that's about $84 more per month, or $30,240 over 30 years.
The lesson: If you think rates might fall, a float-down option or a shorter wait could save you money. But you can't predict the market with certainty.
Scenario B: Rates spike while you wait
You decide to wait for a better rate. Instead, rates jump from 6.875% to 7.5%. On a $350,000 loan, that's an extra $137 per month, or $49,320 over 30 years. Now you're locked into a rate you wouldn't have accepted originally.
The lesson: Waiting is a bet. Sometimes you win, sometimes you lose. The pain of losing is usually bigger than the gain from winning.
Scenario C: Your closing gets delayed
You locked a 30-day rate, but the appraisal takes longer than expected. Your lock expires in 5 days. The lender offers an extension for 0.25% of your loan amount. On a $350,000 loan, that's $875 to extend for another 15 days.
The lesson: Always ask about extension costs before you lock. If there's any chance of delays, build that into your lock window choice from the start.
Questions to ask your lender before locking
Print this checklist and bring it to your next lender conversation. These questions will help you avoid surprises.
Common rate lock mistakes
These are the errors we see homebuyers make over and over. Knowing about them ahead of time can save you real money.
Locking with the wrong lender
Some lenders offer cheap rates but have slow processing times. If your lock expires because they couldn't close on time, you'll pay extension fees or get a worse rate. Ask about their current average closing time before you lock.
Ignoring the float-down rider
Many buyers don't ask about float-down options because they've never heard of them. If your lender offers one, the cost is usually a fraction of what you'd save if rates drop even a quarter point.
Not getting the lock in writing
Verbal rate locks aren't worth the air they're spoken on. Make sure you get a written lock agreement that specifies the rate, the expiration date, the loan program, and all fees.
Trying to time the market perfectly
Nobody knows where rates are heading. Professional traders with billion-dollar budgets can't predict mortgage rates. A rate you're happy with today is a good rate, even if it drops tomorrow.
What this guide assumes
This guide uses typical industry figures for lock fees and float-down costs. Your lender may charge more or less. The monthly payment calculations assume a 30-year fixed-rate mortgage with no PMI, taxes, or insurance included.
Rate change scenarios (plus or minus 0.25% to 0.5%) are examples to illustrate the math. They are not predictions. Actual rate movements can be larger or smaller.
This guide is educational. It does not replace advice from a licensed mortgage professional who knows your specific situation.
Last updated: January 2026. Lock fee structures may change. Verify current terms with your lender.