If you recently signed in to QBO, you’ll see a page asking you to confirm the account you want to sign in under. If it’s the account you want to manage the new company with, select Yes, that’s correct.
If you haven’t signed in recently, you’ll see a page that asks you to create an Intuit account to buy QuickBooks. Below "Buy QuickBooks Online" select Add another company. Enter the same ID and password you already use.
Fill in all the information needed and follow the on-screen instructions to complete the process.