Interest Rates

Rate Locks & Float-Down Agreements

By Marcus Vance Last Updated: June 2026 Reading Time: 2 min (274 words)

Protect your loan pricing against market interest rate volatility during mortgage underwriting and processing.

Key Takeaways & Highlights

1. What is a Mortgage Rate Lock?

A mortgage rate lock is a lender's binding guarantee to hold a specific interest rate, APR, and discount point structure for a set duration (typically 30, 45, or 60 days) during loan processing.

A rate lock protects you from market rate fluctuations while your loan goes through underwriting. If market interest rates climb during your lock window, your lender must honor the locked rate.

2. The Risk of Rate Lock Expiration

Rate locks are time-sensitive. If your lock expires before your loan closes due to processing delays, your interest rate will revert to current market pricing unless you pay a lock extension fee.

To avoid expiration, submit all requested underwriting documents (such as tax returns, bank statements, and pay stubs) to your lender immediately, and maintain regular communication with your loan officer.

3. Float-Down Provisions and Pricing Adjustments

If you lock your rate but market interest rates fall significantly before your closing date, ask your lender about a float-down option. A float-down agreement allows you to capture a lower rate.

Float-down agreements typically carry strict guidelines: market rates must drop by a set percentage (such as 0.25%), and the lender may charge a small fee to execute the adjustment.

4. When to Lock Your Interest Rate

Deciding when to lock your rate depends on market conditions and your risk tolerance. If interest rates are rising and you are comfortable with your quoted payment, lock the rate immediately.

If rates are falling or stable, you can float the rate. Floating means you wait to lock your rate closer to your closing date, though this strategy carries risk if market rates spike unexpectedly.

Marcus Vance

Verified Contributor

Senior Credit & Loan Policy Advisor • Editorial Board

Marcus Vance is a residential financing expert with 12 years of experience specializing in credit policy audits, loan-level price adjustments (LLPAs), and regional property tax assessment patterns. Having worked as a mortgage compliance officer, Marcus reviews calculator models and underwriting guides to verify alignment with current GSE (Fannie Mae & Freddie Mac) and Federal Housing Administration standards.

Focus Areas: FHA Lending CriteriaJumbo Loan StructuresLLPA Optimization

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