How do I add users to my account?
Only the owner and administrators can add users your Twilio Account. Only the owner may add administrators to the account; Administrators may not add additional administrators to the Account.
On your Manage Users page, you’ll be able to choose the permission level you’d like your new user to have. Once you add the user, Twilio will send them an email invitation. They must accept the invitation to have access to your Account.