DEFINITION of 'Prepayment'. The satisfaction of a debt or installment payment before its official due date. A prepayment can be for the entire balance or for any upcoming payment that is paid in advance of the date for which the borrower is contractually obligated to pay it.Examples of a prepayment come in the form of rent or early loan repayments.Next Up.EFINITION of 'Prepayment'. The satisfaction of a debt or installment payment before its official due date. A prepayment can be for the entire balance or for any upcoming payment that is paid in advance of the date for which the borrower is contractually obligated to pay it.