Once a user goes through the contract and clicks the accept button, that contract is locked down. Even the user who made the payment plan choice is unable to adjust that choice once accept is clicked.
After that time, if the Parent realizes they made an error and need to change the payment plan, the school will need to remove the contract from the Student or Candidate, re-add the contract and generate it, then have the Parent fill out the contract a second time.
Note: If the parent filled out a Smart Tuition enabled contract with the incorrect payment plan, assign a non-integrated contract to the student once the original has been deleted. Once the family has selected the correct Payment Plan, update the family's billing information in Smart to reflect the change.