If the Parent has already paid, when he or she reaches the payment screen, it will not prompt for a second payment. It will display a message letting the Parent know that the payment has already been submitted.

You can allow a resubmit by going to Enrollment Management:
  1. Select People Finder
  2. Search for the Student
  3. Select Checklist
  4. Scroll down to the Application section and click Allow Resubmit