If you want to close your user/company account, you can do so from the Account option in the right-side dropdown.
In this area, to the right of your email address, you can close your user account (if you're not an owner), which will remove you from the company account and allow the email address to be used for a new account or to invite you to a separate account.
If you are an owner, you will have the option Close account for all users which will completely close the account.
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