 Balloon payment mortgages have only partial amortization, meaning that amount of monthly payments due are calculated (amortized) over a certain term, but the outstanding principal balance is due at some point short of that term, and at the end of the term a balloon payment is due.When interest rates are high relative to the rate on an existing seller's loan, the buyer can consider assuming the seller's mortgage.A wraparound mortgage is a form of seller financing that can make it easier for a seller to sell a property.