When borrowers use installment credit,theyâ€re taking out a loan for a specific lump sum of money over a set period of time. The borrower pays back the loan in regular intervals over a set repayment period,typically in monthly payments. In addition to paying back the amount of money that they borrowed,the borrower will also pay interest and fees on the loan. Interest rates will vary depending on a borrowerâ€s creditworthiness and the type of installment loan. Learn more