 In the U.S. a partial amortization or balloon loan is one where the amount of monthly payments due are calculated (amortized) over a certain term, but the outstanding balance on the principal is due at some point short of that term.In the UK, a partial repayment mortgage is quite common, especially where the original mortgage was investment-backed.Graduated payment mortgage loans have increasing costs over time and are geared to young borrowers who expect wage increases over time.