This document provides a sample payoff request letter that can be used as a guide. 2) Once you receive the principal payoff letter, write the check for the exact amount and in the memo, write: "Payoff" and the mortgage account number.Are you considering refinancing your mortgage? Team Clark is here to walk you through this difficult process step-by-step. Filling out this form is straightforward. That deposit represents the equity you have in the property before you start paying off the mortgage loan. 1. 1. Enter the name and contact information of the mortgage servicer. Mortgage Payoff Calculator – The Impact of Making Extra Payments.