If you’re paying more than your minimum monthly payment, extra funds are first applied to any accrued interest, then the principal loan balance, and finally to fees (if applicable).
If you’d like to make a payment directly to your principal balance, you can make an additional payment within the same billing cycle after completing your minimum payment. As you repay your loan, please keep in mind that interest accrues daily.
Learn more about how interest accrues or how payments are applied: