If they complete their PhD during the academic year, they can continue to do any planned contracted work in their role as a PTA until the end of the academic year (subject to Tier 4 expiry which may mean their contract will finish earlier).

In the event that a student withdraws from their PhD studies and ceases to be registered as a student with the University, the University will usually take steps to terminate the employment. However, each case will be assessed independently by Human Resources, following consultation with the line manager. If appropriate, the University may apply discretion in allowing the student to continue to do any planned contracted work as a PTA until the end of the contract (subject to Tier 4 requirements).  

In the event that a student interrupts their PhD studies for a temporary period, provided that the student remains registered as a student with the University and the circumstances for the interruption are discussed with the line manager, the University will apply discretion in allowing the student to continue to do any planned contracted work as a PTA until the end of the contract (subject to Tier 4 requirements).