You may cancel your registrationbefore the first day of class by using myUK.
All students wishing to leave the university during a term (fall, spring, summer or winter) must formally withdraw. More information can be found on the website for the University Registrar here.
A retroactive withdrawal allows a student to petition a group of faculty to withdrawal from all classes after the term has ended. In order to be considered for this, a student must have experienced an extinuating circumstance, such as injury, illness, or other serious personal issues. More information can be found here.