Delinking your bank account from QuickBooks Online is easy peasy. I'd be happy to guide you through the process.
Before we proceed, please know that disconnecting bank accounts only stops QuickBooks from downloading new transactions and does not change your existing accounting data.
Once you're ready to delink your bank account, you can follow the steps below:
Sign in to your QuickBooks Online (QBO) account.
Click Transactions/Banking from the left menu.
Choose the bank account you want to disconnect. Then, click the pencil icon.
Select the Edit account info button.
From the Account window, put a checkmark to the Disconnect this account on save checkbox.