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A mortgage rate lock fixes your interest rate between your lender’s offer and closing, so a rise in market rates does not change your loan. The Consumer Financial Protection Bureau says locks are typically available for 30, 45 or 60 days, and extending one may be expensive. With the 30-year fixed rate at 7.24% in Freddie Mac’s survey for Oct. 29, a quarter-point move changes the payment on a $400,000 loan by about $68 a month.
How a mortgage rate lock works
The CFPB says a lock means your interest rate won’t change between the offer and closing. It covers the rate only. Without a lock, the rate can change at any time. The lock holds if you close within the lock period and your application does not change.
| Question | What the CFPB says |
|---|---|
| What is locked? | The interest rate, for the lock period |
| How long are locks? | Typically 30, 45 or 60 days, sometimes longer; policies vary by lender |
| When does the lock start? | Some lenders lock when they issue the Loan Estimate and some do not |
| Where do you check? | Page 1 of the Loan Estimate shows whether the rate is locked and for how long |
| What does it cost to extend? | The Loan Estimate does not show the price of a lock period or an extension |
Rates also differ by day. The CFPB’s Loan Estimate guidance notes that interest rates can change daily, so two quotes issued on different days may differ because the market moved.
Mortgage rate lock or float: the trade-off
Locking and floating each carry a cost. A mortgage rate lock removes the downside of a rising market and the upside of a falling one. Staying unlocked leaves both open.
| Choice | What you gain | What you risk |
|---|---|---|
| Lock | A fixed rate through closing, if you close on time and the application is unchanged | Missing a lower rate if the market falls; an extension fee if closing slips |
| Float (no lock) | The chance to close at a lower rate if the market falls | A higher rate and payment if the market rises, since the rate can change at any time |
Market direction is not knowable in advance. Weekly moves in the Freddie Mac survey have been small lately: the 30-year rate eased from 7.32% to 7.24% in one week, a $22 change in the monthly payment on $400,000, but it stood well above the 6.17% of a year earlier. A mortgage rate lock matters most when your budget cannot absorb a quarter-point rise.
What a quarter-point move costs
The table uses the 7.24% Freddie Mac average as the starting point. Payments are principal and interest only on a $400,000 30-year fixed loan, our own calculation, before taxes, insurance and fees. Our Freddie Mac rate report shows the same $2,726 figure for 7.24%.
| Rate at closing | Monthly payment | Change vs. 7.24% | Change per year |
|---|---|---|---|
| 6.99% | $2,659 | -$67 | -$810 |
| 7.24% | $2,726 | Baseline | Baseline |
| 7.49% | $2,794 | +$68 | +$818 |
| 7.74% | $2,863 | +$137 | +$1,643 |
If a quarter-point rise held for all 360 payments, the extra cost would be about $24,500 in interest over the life of the loan. A lock protects against that move. It also gives up the matching saving if rates fall by the same amount, and the CFPB warns that a lock can keep you from a lower rate.
Match your mortgage rate lock to your closing date
A lock that ends before closing can force an extension or a new rate. The table shows how many days of cushion each standard lock leaves, counting from the day you lock.
| Days from lock to expected closing | 30-day lock | 45-day lock | 60-day lock |
|---|---|---|---|
| 21 | 9 days to spare | 24 days to spare | 39 days to spare |
| 35 | 5 days short | 10 days to spare | 25 days to spare |
| 50 | 20 days short | 5 days short | 10 days to spare |
Our rule of thumb: pick the shortest standard mortgage rate lock that leaves about 10 days of cushion. That is a planning heuristic, not lender policy. Ask what a longer lock costs before you choose, since the Loan Estimate will not show it.
The mortgage rate lock timeline
| Stage | What happens | What to check |
|---|---|---|
| Loan Estimate | Lender issues the estimate after your application | Page 1: is the rate locked, and for how long? |
| Lock decision | You lock now or wait, depending on the lender’s policy | Rate, lock period and expiration date, in writing |
| Processing | Appraisal, credit and income documents | Avoid new debt and undocumented income; both can change the rate |
| Closing | Loan funds and the rate takes effect | Closing must fall inside the lock period |
The second column follows the CFPB’s description of the process. The advice to get terms in writing is ours. A mortgage rate lock is only as good as its stated terms, so ask for the period and expiration date before you rely on it.
What can still change a locked rate
The CFPB lists changes that can alter a locked rate or the loan terms. Most trace back to the application.
| Change | Why it matters |
|---|---|
| Loan type or down payment | The lock was priced for the original application |
| Appraisal higher or lower than expected | Changes the loan-to-value ratio |
| Credit score change, such as a new loan or a missed payment | Changes the borrower’s risk profile |
| Overtime, bonus or other income the lender cannot document | Changes the income the lender can count |
Questions to ask before you lock
| Ask your lender | What the answer tells you |
|---|---|
| What does it mean if I lock my rate today? | Exactly what is fixed and what is not |
| What lock period does this Loan Estimate provide? | Whether it covers your closing date |
| Is a shorter or longer lock available, and at what cost? | The price of cushion |
| What if my closing is delayed and the lock expires? | The extension terms |
| Could my rate still change after I lock? | The conditions above |
| If I lock and rates go down, what happens? | Whether any float-down option exists |
The CFPB does not mention float-down options in its lock guidance, so ask each lender directly and get the answer in writing. For the wider rate picture, see our running page on mortgage rates today and our note on what the Fed’s hold means for mortgages.
Editor’s Take
A mortgage rate lock trades flexibility for certainty. Nobody knows whether rates will rise or fall before closing, and the CFPB says plainly that a lock can cost you a lower rate. The decision turns on how much a quarter-point change would strain your budget, how firm your closing date is, and what the lender charges for a longer lock.
This is general information, not financial or mortgage advice. Lock terms vary by lender; confirm yours in writing.
