Answer: unpaid principal balance.
Explanation: unpaid principal balance is that portion of a loan that has not yet been paid back to the lender by the borrower. The balance represents the remaining risk of nonpayment being incurred by the lender. Unpaid principal balance is the portion of a loan at a certain point in time that has not yet been remitted to the lender. The original unpaid principal balance is the amount borrowed, and therefore, the amount the borrower owes the lender on the origination date of the loan.