When a user registers on the platform it is uniquely identified by his email. New users usually get a fresh new opensource account, but if their email domain is recognized to be of a company that has a paid account in Meterian, then the new user is added to that account. Note that there are obvious exclusions such as the usage of a "free" email is used, like "gmail.com" or "hotmail.com",
So, if the company "acme.com" starts a paid subscription to Meterian, then all the users with an email in the same domain will be added automatically to such account.
It is also possible to group user in an account based on the Github organisation they belong to. This is available for organisations on GitHub, and it can be set up using the Meterian dashboard.