Welcome to the Community space,
I am here to provide insights about creating an account in QuickBooks Online (QBO).
QuickBooks Online lets you have multiple companies under the same QBO account. However, each company file needs to be paid for its subscription.
Also, you can add users to your business account depending on your subscriptions and not for three separate businesses.
Moreover, I'm adding this article as your reference in using one email for all QuickBooks Online companies: Use one user ID to access multiple companies in QuickBooks Online.
Return to this post if you have other concerns about your adding users to your QuickBooks Online account. I'll be here to lend a hand.
