When to lock your rate (how long & float-downs)
Locking protects you from rate jumps while you close. Here’s when to lock, how long to choose (30/45/60+ days), how extensions & re-locks work, and whether a float-down is worth it.
What a rate lock is (and isn’t)
- Is: A commitment from the lender to honor a specific rate/cost for a set number of days.
- Isn’t: A guarantee you’ll be approved—underwriting conditions still apply.
Rate locks are usually available once you’re under contract. Some lenders offer “Lock & Shop” before contract—often at extra cost or with tighter rules.
When to lock (timing)
- Under contract? Most buyers lock shortly after the offer is accepted, once key terms (price, closing date) are set.
- Volatile market? Lock sooner to avoid spikes; consider a float-down if you want downside protection.
- Stable/declining rates? Some buyers float briefly until appraisal/inspection, then lock. Risk: rates can jump.
Use the Mortgage Payment Calculator to see how small rate moves affect monthly budget & DTI.
How long to lock
Common lock periods
- 30 days — lowest cost, tight timelines
- 45 days — common for financed purchases
- 60+ days — more cushion; usually prices higher
Pick a lock length
- Count days from today (lock date) to your closing date.
- Add buffer for appraisal, title, condo/HOA review, and any contingencies.
- Choose the next lock tier that safely covers it.
Longer locks usually add cost via slightly higher rate or fees. Ask your lender to price multiple lock lengths so you can compare.
Float-down options
A float-down lets you reduce your locked rate if the market improves during your lock period—usually once, and under specific rules.
- Often requires a significant market move and/or a fee/points.
- May be time-limited (e.g., only in the last 15–30 days before closing).
- New rate is typically a set amount above current market, not the absolute lowest print.
If rates rise, your original lock stands. If they fall, a float-down can help capture part of the drop.
Extensions & re-locks
- Extension: Adds days to your current lock if closing slips; usually costs a fee or small rate bump.
- Re-lock: If a lock expires, lenders may re-lock at current market pricing; some allow a short “re-lock within X days” policy.
- Change of terms: Program/points/credits or property changes can require re-pricing.
Ask your lender to outline their extension and re-lock policy in writing so there are no surprises.
Comparing lock quotes
Match assumptions
- Same lock length (30 vs 45 vs 60)
- Same points/credits
- Same program, occupancy & property type
Ask explicitly
- Float-down availability & rules
- Extension fee schedule
- Re-lock policy and costs
Quick checklist
- Lock after contract acceptance; choose a period that covers to closing + buffer.
- Price 30/45/60-day options—compare total cost (rate + points/credits).
- Decide if float-down is worth the fee/rules in your scenario.
- Get extension & re-lock policies in writing.
Disclaimer: Educational info, not financial advice. Policies and pricing vary by lender, loan type, and state.