If I want to run another business with Quickbooks Online, do I need to register it completely seperate to the business I am running now?
That's right, budgetstoragekin.
One QuickBooks subscription is for one company only. To add another, simply log out of your Intuit account (QuickBooks company) to return to the Sign-in page. Then, click the Sign up hypertext in blue text to select a plan.
After selecting a plan, you'll be asked to create an Intuit account. Since you already have one, just click Sign in on Adding a company to an existing account? Sign in. Then, enter the credentials you use when signing in to your existing QuickBooks company.