How to add user created account to my organizatrion?

I guess that you meant "add user extension to an account", right?

I still don't understand what you wrote "... set up an account on his own through the web instead of letting us create his account in the portal...". What is that "web" and that "portal"?

Basically, only the account admin users can add new user extension to an account. Each user extension must have a unique email address for the extension validation process. If an extension is created but not assigned to a user, you will find the extension under the "unassigned extension" page from the account service web.

Chris,

The only action I have found around this issue is to have the user log into their 'personally created' RC account and change the email address to a personal email address. This will free up the company address to use in creating their company account. The other option is for them to call RC directly (do not submit a problem ticket!!) and have RC delete the personal account and all reference in the system to the email address. I have found the first option 100% favorable to the second as deleting the personal account can sometimes leave the email address in their system and will need more phone support to track down and remove.