Fortress Bank provides the community with sound financial solutions for business and personal use from our nine banking centers in Illinois and Iowa. If you're interested in learning how, please fill out this form and we'll be in touch.It lays out each fee and dollar still due before you completely pay off your mortgage. Here's how it works. Need to make a payment? Fortress Bank understands and our website provides the tools to make the whole process that much easier. 1. 1. Enter the name and contact information of the mortgage servicer. A mortgage payoff letter can come in two forms. One form tells borrowers the remaining principal amount and interest they have to pay to close out the loan. Mortgage investors in the 1940's.