There is no overall limit of users / employees that belong to a company. Please note, however, that the number of employees that can be added to your account depends on the subscription package purchased. If the employee limit on a given account is exceeded - the new employee will receive an error message:
In order to add another user / employee, you must purchase an additional position to your package at: https://easysolar.app/en/product/additional-user-subscription-payment/ The quota will then be changed and the added employees will be able to join the company.