Can I have tabs open for multiple companies at a time?

If you want additional automation with multiple accounts, integrating a 3rd party tool like Zapier is useful. Buffer even writes about this here: https://faq.buffer.com/article/596-publish-ifttt-accounts

To answer your question, no you can not open multiple tabs with each one hosting a different company. The only way to do this is to use something like Chrome Incognito window and you would have to open a window for each company. Unfortunately, if you are logged into one Buffer account that transfers over to any tab you open that is within the same window as the one you have opened. Hope this helps.

I have one Buffer account with multiple clients on that one account, so I just click on which platform/client I want to work on within that (so just one tab). If each client has its own Buffer account, you'd have to log in to their individual accounts in order to use the platform.

If you own the account, you can add multiple businesses/companies to your account. If you're logging in to each business / company (they own the account and you're managing it), you have to log in and out of each one to use it. Hope that helps! :)