Hi there,
It's important that you have the correct product for each region that you have a business in. Intuit accounts are a great way to have access to QuickBooks, Turbotax and Profile products from one login. I can provide some information about emails relating to Intuit accounts.
An email can only be associated with one Intuit account. If you'd like to be able to have two different accounts for each region, they would each have their own email address.
If you have any other questions, feel free to reach out here.