Firm staff will have access to all Client Accounts unless restricted by Groups or SSO Access Control.
Groups can be used to narrow which firm staff has access to which client accounts. Firm Administrators always have full access. Groups are added to LeaseCrunch then selected on the Add/Edit Client Account screen.
When adding client users, you can always ensure you are in the correct client account by viewing the client name on the top right. Users added at the client account will only have access to the client account.