lock-in period

Rate Lock

An agreement between a mortgage bank and a potential borrower promising that that the bank will not change the proposed interest rate on a loan that has not been concluded for a certain period of time. The rate lock usually lasts for 60 days.
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lock-in period

(1) The period of time during which a loan may not be prepaid.(2) The period of time during which a lender will guarantee a certain interest rate on a loan to be extended by it in the future.

The Complete Real Estate Encyclopedia by Denise L. Evans, JD & O. William Evans, JD. Copyright © 2007 by The McGraw-Hill Companies, Inc.