Go to Help > License.
This will show the current Indigo licenses, such as the number of licenses used for Companies, Payroll Employees, T&A Employees, the subscription expiry date and the total licenses.
Use the 'Export Licence Report' button to get a full list of how the licences are used for each company. Note that you would need to be a Subscription Administrator to issue this report.
More information about Purchasing Additional Licenses can be found here.
To learn how to add a new company to your current license, click here.