Adding another LLC to an already existing quickbooks account to access from the same login
You'll be glad to know that you can use one login credential to multiple companies, Icdlllp.
Yes, you can have more than one QuickBooks company (account) with the same email address. Just make sure to create a new company file for your online business. The steps below will guide you on how to create it:
How to create a new company file in QuickBooks
Open QuickBooks Desktop. Since you already have a company file, I'd suggest you press and hold the Ctrl key, and don't release it until you have the No Company Open window.
On the No Company Open window, select Create a new company.