To create an ACR account or look up your SSO number, log into the http://www.acr.org/ website.
On this site, you may create a free account or log into your existing account to review your account information. If you need to create an ACR account, select the "Create an Account" (<-click hyperlink) button and enter the required information.
To update your login information or locate your SSO account number (Customer ID), log in using your ACR account credentials and go to My ACR. Locate the Customer ID number in the membership box.