Once the loan is considered in default, the entire balance (principal, interest and collection fees) is immediately due and payable. If you default, it means you failed to make payments on your student loan according to the terms of your promissory note, the binding legal document you signed at the time you took out your loan. In other words, you failed to make your loan payments as scheduled. Your school, the financial institution that made or owns your loan, your loan guarantor and the federal government can all take action to recover the money you owe.