What do we call the time period during which an interest rate is guaranteed to a borrower?

The time period during which an interest rate is guaranteed to a borrower is referred to as the "lock in period." During this time, the lender ensures that the borrower can secure the specified interest rate, protecting them from potential increases in market rates. This is particularly important in real estate transactions where fluctuations in interest rates can significantly affect mortgage payments and overall financing costs. The lock in period is essential for borrowers who want certainty about their future payments, allowing them to plan their budgets accordingly.

In contrast, the other terms do not accurately describe this period. The "fixed period" typically refers to fixed-rate mortgages but does not specifically denote the guarantee of a rate over a designated period. "Guaranteed period" is vague and doesn’t address the specific context of interest rates in lending. The "adjustment period" is related to adjustable-rate mortgages, where the interest rate may change after a specified time, but it does not imply a guarantee of rates. Thus, the term "lock in period" is the most precise and widely accepted term for this concept in real estate financing.