If you already have a QuickBooks Online account, you can still add additional company files.
- Go to https://quickbooks.intuit.com/choose-country/ . Choose your country to be directed to your region specific QuickBooks Online website.
- Select a product (Simple Start, Essentials or Plus).
- Click Start Free Trial or "Buy Now".
- On the next screen you may get option to either continue to create free trial (Continue to Trial) or buy now for a discounted price.
- Since you already have an account with Intuit, click on "Add another company?" link located at the top of the screen.
- Enter your Email Address (User Id) and Password.
- Click Add new company.