Hi there, info856.
Yes, you can open another account. You'll need to sign-up or subscribe for a new QuickBooks Online to create another company. One company file is equivalent to one subscription. And, each company you add will have a separate paid subscription.
You can put this company under your existing Intuit ID. To do that, you'll have to log in to your current company or use the same login credentials when creating a new account.
Here's how:
1. Go to https://quickbooks.intuit.com/uk/pricing/ .
2. Choose the product you wish to use (Simple Start, Essentials, Plus).
3. Hit either Buy Now or Free 30-day trial.
4. Select Already have an account? Sign in.
5. Sign in with your current user ID and password for other company subscriptions. Follow the on-screen instructions to set up a new subscription under your existing login.
Once done, you can simply switch from one company to another quickly. Please check this article to see the steps: How do I switch companies?.
If there's another user set up under your user ID, you can set up a separate and unique User ID/password for them. You can refer to this article on how to perform the steps: One company listed multiple times.
Please let me know if you have other questions related to QuickBooks. The community is always here to help you.