Can we use the paid Convertkit account for two websites? Or we need to have separate Convertkit account for separate websites?

You can run two websites on the same account. Although it's generally cleaner to have two different accounts. 

If you run it on the same account, you can add an email address for each. And then when you send a broadcast email, just make sure you are using the email address for the relevant website. Same with sequences. 

A couple of downsides to running it on the same account:

• If someone unsubscribes, they'll unsubscribe from both
• Tags can get messy, depending on how many you have
• The default email address is one email address, so you'd need to change that for every sequence and broadcast

ConvertKit recommend that if audience is different, then use different accounts. If the audience is the same, then one account is probably fine. More on that here: https://help.convertkit.com/en/articles/2502514-can-i-use-one-convertkit-account-for-multiple-domains-or-businesses171

Hey @Omid 39, absolutely! you can use 1 ConvertKit account for multiple websites. It would be a lot easier to manage everything in one account as well as cost-effective.