The sale of a mortgage in the secondary mortgage market with terms that require the seller of the mortgage to make delivery to the buyer by a certain date or pair-out of the trade. The requirement to make delivery of the mortgage or pair-out of the trade makes a mandatory mortgage lock different from a best-efforts mortgage lock. A mandatory mortgage lock also carries more risk for the seller of the mortgage. 



|||Mandatory mortgage locks or trades generally command a higher price in the secondary mortgage market than best-efforts locks. This is because there are fewer hedge costs associated with mandatory mortgage locks.