Let me help you delete your bank account in QuickBooks Online (QBO), matt-slidinglodg.

When your bank account is connected to an online banking feature, you'll need to disconnect the bank connection first before removing it. Let me guide you on how.

1. Go to Transactions, then select Bank transactions (Take me there).
2. Once on the Bank transactions tab, choose the Bank Account you want to delete.
3. Tap the Pencil on the top right of the Account.
4. Click Edit Account Info.
5. Scroll to the bottom and tick the Disconnect this Account on Save box.
6. Press Save and Close.

This account will not appear on this screen anymore, however, the chart of accounts will still be active in the Accounting tab. If you wish to make your account inactive, please follow the steps below:

1. Hover your mouse to Accounting, then select Chart of Accounts.
2. Click the Account history drop-down under ACTION.
3. Select Make inactive.
4. Press Yes to confirm.

Also, the inactive account contains transactions, they will remain in your company file including your reports. You can check this article on How to handle the deleted account. Additionally, QuickBooks automatically downloads the most recent transactions and matches them to the ones you've already recorded. Just visit this article for your reference: Categorise and match online bank transactions In QuickBooks Online.

On the other hand, if you need to start over the entire company file, just follow the steps and details in this article: Delete your data and start over in QuickBooks Online.

I'm always around and ready to help if you have more questions about managing your bank transactions in QBO. Just click the Reply button to add your comment so I can assist you further. Keep safe.