Any level of account, Free, Basic, Lite or Pro can add unlimited users to their account. The only limit is the number of credits.
How to add a user to your account
Select "Team" from your user icon in the top right-hand corner.
This will show you a screen with your current team members.
If you are an account owner or admin, you will see an "Invite user" button. Click this button.
Users are added via email address. Enter the email address of the user you wish to grant access to and click the "Send invite" button.
Once this invite has been sent, you will see their email added to the user list along with an "Invite Sent" notice.
This user will receive an email with a confirmation link and if they do not have an account, they will have to sign up to AlsoAsked (for free). Once they have completed this process, they will be added to the account as a "member".
Changing user roles
As an owner or admin, you can change the role of other users simply by clicking the dropdown of their current role. Admins can be changed to members and members may be granted admin status so they can invite other users.
Removing users
To remove a user's access, simply click on the bin symbol next to them. You will be given a confirmation box, after which they user will be instantly removed and logged out.