You cannot delete a bank account in QuickBooks Online (QBO), pmpfl-aol. You can only make it inactive to hide it from view. I'm here to guide you through the steps.
If the bank is connected to online banking, you'll have to disconnect it from the banking page to remove it.
Here's how:
Go to Transactions and choose Bank transaction.
Click the tile for the bank account.
Hit the Pencil icon, then select Edit account info.
Tick the Disconnect this account on save checkbox.