This is from FAQ of Scotiabank application guide. This information can differ depending on the bank.
Q. I have deferred my enrollment or changed my educational institution, but have already funded my Scotia Investment Account or have not funded my Scotia Investment Account. Can I still use the same Scotia Investment Account to apply for my Study Permit?
A. Yes, you may use the same Scotia Investment Account Number. In order to do so, send your new offer letter/ acceptance letter including your new date of arrival to Scotiabank. Your email to Scotiabank must be REPLY only to the last message received from the Scotiabank Secure Email Service mail box. The subject line of your email must state: Scotiabank Student GIC Program- Your Full Name (Given/First and Surname/Last)- Enrollment Update- School Change