Every customer is assigned a "Site" ID and Password. Your Site ID is unique to your business and cannot be changed. Your password is personal to you and can be changed as often as needed. Please protect your password and change it whenever you feel the need. This will prevent unauthorized access to your private management system, which stores guest details, credit cards, and other private business information.
If you are an Owner of a Unit(s) that is using BookingCenter as a PMS, then you are an 'Owners Channel Manager User' and your login and ID is provided by your HOA/Property Management Company. You can learn more on this at the Owners Area documentation here.