4. Obligation for instalment payment plans for tuition fees. You understand and agree that if you are authorized by the University to pay your tuition through a tiered payment plan, you must enter into and sign a separate instalment payment agreement before registering the courses. You understand and agree that if credit remains in your account, if course enrollment is open, you may not enroll in courses unless you have entered into a separate installment payment plan agreement and have signed. You must sign a tiered plan for each academic year in which tuition fees are paid in instalments or, alternatively, the instalment payment agreement you sign must explicitly state that it covers several academic years and list the years it covers. Late charges for amounts that have not been paid in a timely manner under your instalment payment contract will be assessed in accordance with the terms of the instalment payment contract. The guidelines and the procedure for official voluntary exit from the university are available under htto://www.purdue.edu/dfa/contact/policies-appeals.html#withdrawal. Guidelines and procedures for involuntary discharge from the university are available at www .purdue.edu/studentregulations/student conduct/invwithdrawal.html. You understand and agree that if you drop out or withdraw certain or all courses for which you register, or if you must resign in accordance with the Involuntary Payments Directive, you are responsible for paying all or part of the tuition fees and fees in accordance with the Title IV Refunds and Returns of Funds Directive to the following address: www.purdue.edu/business/bursar/payments/refunds.html. . .