Your student ID number is a 9 digit number. For new students starting in 2021/22, your ID number will likely begin with '21' e.g. 212345678. It may have previously been referred to as your applicant number and will appear in a number of communications from us, such as your invitation to complete Online Enrolment and the email you received informing you about ID card collection.
It is the username that you use to access MySIS and it is also displayed within MySIS, within the 'My Details' tab.