Between the day you apply for a mortgage and the day you close, interest rates can move significantly. A rate lock freezes your interest rate for a set period, protecting you from increases during the loan processing period. Getting the timing right can save — or cost — you thousands of dollars.
A mortgage rate lock is a commitment from your lender to hold a specific interest rate and points for a defined period, typically 30 to 60 days. Once locked, your rate will not change even if market rates increase. If rates drop after you lock, your locked rate stays the same unless you have a float-down provision.
Rate locks are free with most lenders for standard lock periods (30-45 days). Longer lock periods (60-90 days) may carry a small cost, typically 0.125-0.25% of the loan amount, because the lender assumes more risk over a longer timeframe. Some lenders build this cost into a slightly higher rate rather than charging an explicit fee.
The ideal time to lock depends on your risk tolerance and market conditions. Most borrowers lock when they have an accepted purchase agreement and are confident the deal will close within the lock period. Locking too early risks the lock expiring before closing; locking too late risks a rate spike.
If rates have been moving up and down significantly, locking at application gives you certainty. You know exactly what your payment will be, which helps with budgeting and qualification. In markets where rates have risen 0.5% or more in recent weeks, locking immediately is usually the right call.
If rates have been declining and the trend looks likely to continue, you might float — meaning you delay locking in hopes of catching a lower rate. This is a gamble. Floating saves money when rates drop but costs money when they spike. Most financial advisors recommend locking once you have a rate you can comfortably afford, rather than trying to time the bottom.
For most buyers, the best strategy is to lock within 1-3 days of having an accepted offer. This gives you the longest possible lock period and protects against rate increases during the 30-45 day closing process. Trying to time the market with your single largest financial transaction is rarely worth the stress or risk.
Match your lock period to your expected closing timeline plus a small buffer. If your closing is scheduled in 30 days, lock for 45 days. If closing is 45 days out, lock for 60 days. The buffer protects you if closing is delayed due to appraisal issues, title problems, or underwriting conditions.
Standard lock periods and their typical costs: 30 days is usually free or built into the rate, 45 days is free with most lenders, 60 days may add 0.125% to your rate, and 90 days typically adds 0.25% or more. New construction purchases often require extended locks of 90-180 days, which carry higher costs.
If your lock expires before closing, you face the current market rate — which could be higher or lower than your locked rate. Most lenders will offer a lock extension, typically for a fee of 0.125-0.375% per extension period (usually 7-15 days). These fees add up quickly, so it is critical to set a realistic lock period upfront.
Some lenders offer a one-time free extension of 7-15 days if the delay is not your fault (such as a title issue or appraisal delay). Always ask about extension policies before locking. If your closing is delayed significantly, you may need to re-lock at current market rates, which could change your payment substantially.
A float-down provision allows you to reduce your locked rate if market rates drop by a certain threshold (typically 0.25-0.50%) before closing. This gives you the protection of a lock with the upside potential of a rate decrease. Float-down options are not free — they usually add 0.125-0.25% to your rate or cost an upfront fee.
Whether a float-down is worth it depends on rate volatility and the cost. In a market where rates are bouncing around, paying 0.125% for float-down protection that could save you 0.5% makes mathematical sense. In a stable rate environment, you are paying for insurance you probably will not use.
Get everything in writing. Your rate lock agreement should specify the exact rate, points, lock period, and expiration date. Verbal commitments are not enforceable. Keep a copy of the lock confirmation email or document.
Compare lock policies across lenders. Some lenders offer free locks for longer periods, free float-down provisions, or free extensions. These perks can be worth more than a slightly lower advertised rate from a competing lender with rigid lock terms.
Do not let a rate lock drive you to rush the home search. Some buyers lock a rate before having an accepted offer, then feel pressured to find a home before the lock expires. This leads to compromising on the home — a far more expensive mistake than losing a favorable rate. Lock after you have a deal, not before.
Mortgage rates move based on the bond market, particularly the yield on 10-year Treasury notes. When bond yields rise, mortgage rates typically follow. Key factors that move rates include Federal Reserve policy decisions, inflation data (CPI, PCE), employment reports, GDP growth, and geopolitical events that affect investor risk appetite.
Rates can move 0.125-0.25% in a single day after a major economic report. The monthly jobs report (released the first Friday of each month) and CPI inflation data are the two biggest market movers. If you are floating and a major report is coming, consider locking the day before to avoid potential volatility.