Who must request satisfaction of a mortgage in writing?

The borrower is required to request satisfaction of a mortgage in writing because they are the party directly involved in the loan agreement and hold an interest in ensuring that the mortgage is formally acknowledged as paid off. When a mortgage loan is fully repaid, it is the responsibility of the borrower to initiate the process of obtaining a satisfaction document. This written request serves to protect the borrower's interests, ensuring that there is official documentation confirming that their obligation under the mortgage has been fulfilled.

Other parties, such as the lender, title company, or any interested party, may be involved in the mortgage satisfaction process. However, it is specifically the borrower's role to make that formal written request, as they are the party who has the most vested interest in officially concluding the loan agreement.