After reading the info in the given link which says:
August 15 -
All forms relating to your Payment Plan and Funding Options are due in Gilmour Hall 209 (i.e. EASIF, MPPContract, Sponsorship Letters - Int’ Grad students).
September 1 -
Payment Deadline Date: Refer to "Balance Forward" line on your Payment Agreement. A $35.00 Payment Agreement Default Fee will be assessed to those missing payment by this date
So - we don't have to pay anything till September 1st right? August 15th is just the deadline for forms relating to the payment agreement right?