Welcome, and thank you for coming to the Community for help. I'll be guiding you on how you can delete the account lines that are associated with old online banking accounts. In QuickBooks Online, you can delete accounts that are no longer in use. Deleting accounts doesn’t erase their transactions, so your reports won’t change. However, the accounts will be listed as "Deleted". You can also restore deleted accounts any time.
If there are no transactions on the register, then you can merge the account into another instead. Because there are no transactions on the register, it won't have a negative impact on the account it's merged into. Down below, you will find steps for how to delete an account, and how to merge one account into another:
Delete an account:
Select the Gear icon on the Toolbar.
Under Your Company, choose Chart of Accounts.
Find the account you wish to delete.
In the Action column, select the drop-down, then Delete.
Once completed, the account lines will no longer appear on your Chart of Accounts. Be sure to let me know if you have any questions about this information. I'll be here in the Community if you need me.
Quick question. Was there a reason these accounts were created in the first place? I am thinking about work down the road - if they are accounts you don't need now, but may need in the future, I'd recommend making them "inactive" rather than outright deleting them.
This way, you can organize your accounts around a future/ideal state. Saves work down the road as well!