Hey @Walter56
Thanks for asking about multi account best practices. Happy to help.
In the majority of cases, Klaviyo works best as a 1:1 sync with your ecommerce store. Because of this, you may have multiple stores and thus, multiple Klaviyo accounts. You can access multiple Klaviyo accounts using the same email address and password, making it easy to keep track of each account without having to log out and log back in using a separate email address. As long as there is only 1 Klaviyo onsite tracking snippet per domaine, you shouldn’t have to worry about mixing data. In my experience, when someone tries to manage multiple stores from one account is when the data become unclear. The article I linked above will go over this is more detail! Also check out these other community post on the same topic.
Hope this helps! Thank you for being part of the Klaviyo Community!