Create a new user, and choose to link it instead of creating another Company Account
You can create a new user, and once you've activated the user you will be presented with an option to either create a new account or join an existing account.
This is recommend so that you don't have to use the same set of credentials that your Metered License Agent service uses for API-level access to the metered license database server.
Choose one of the Company Account email addresses for the verification step
In order to join an existing account, you must know (and have access to) one of the email addresses that are listed as either the reporting or billing contacts for that account.
You'll enter in that email address, and an email will be sent to the that address with a link in it.
Click on the URL in the "account association" email
Similar to when you activated your new user account, simply click on the link in the email and that user account will be associated with the company account. You'll be taken back to the Metered Licensing portal and shown a confirmation dialog.
If you're already (or still) logged into the portal with the new user account, just refresh the browser window to see the new account, or log back in.
The email sent will have a subject line of "User request to join a Metered Licensing Company Account"