How many characters are required in the username and password? Both the username and password must have at least 8 characters. There is no upper limit. The password is case sensitive. Related ArticlesWill I be reminded before my registration expires? August 25, 2015 I have forgotten my ACS username/password. What should I do? August 25, 2015 Do I have to log in to access resources if I am using a computer from my health service? August 25, 2015 Can I register using a personal email address? August 25, 2015 Do I include spaces when registering my telephone number? August 25, 2015