If anyone is involved in your campaigns, you should add them to your Workado account. You aren't charged based on users, so get them involved!
This will help you to remain organized.
The three user types are:
1. Admins
2. Employees
3. Contractors
Contractors just have access to Campaigns and to Settings to change their password. They are not able to add new campaigns or delete anything.
Employees can do everything aside from update billing details, and create Admin level users.
Admins can update billing information and create other admin users.
Don't think of these roles in terms of your actual designation with the IRS. If you have a contractor who is more like an employee, you can give them Employee status.
The idea is that Contractors from outside your agency can be granted access without the risk of them doing harm to your system should things go wrong.