Someone please advise, currently we having one essentional plan for 1 company,we want to add another company. can we add new company within same plan? if yes then how ?

Let me explain some details on this to give awareness of what you are supposed to do, Ea-director.

In QuickBooks Online (QBO), you can have multiple companies under the same Intuit account with the same plan. However each company file has its own paid subscription, and you're able to access them with the same sign-in information. This lets you quickly switch between companies letting you manage your business efficiently.

You can go to the QuickBooks pricing page and select the subscription option you want. This opens one of two experiences:

• If are already signed in to QuickBooks, you’ll be asked to confirm the account you want to sign in with. If the account displayed is the one you want to use for the new company file, select Yes, that’s correct.
• If you haven’t signed in recently,  you’ll be asked to create an Intuit account. Don't fill this out unless you want to connect your new company file to a new account. Below "Buy QuickBooks Online" select Add another company. Sign in with the user ID and password you already use for QuickBooks.

Follow the on-screen instructions to create a new company file.

Aside from that, learn how you can switch between company files that you want to work with. This article will show you how to create a company file: Add Another Company File to QuickBooks Online.

In addition, familiarize some of the main features to learn more about how to get your business up and running. Go through this handy article for future reference: Get Started with QuickBooks Online.

You can always comment below for further assistance when adding a company. Always know that we're always right here to cover all your needs. Have a nice day!