How can I delete all expense transactions at once after all banks have been removed?

Just to clarify. Do you wish to remove expense transactions in bulk, or reset all transactions completely including income/revenue transactions?

Hi jacky8, 

Welcome to the Community! QuickBooks Online makes managing you business flexible and simple. I can explain how to delete unwanted expense transactions. 

In QuickBooks Online, you can void multiple transactions at one time, however you must delete transactions one at a time. The program is designed this way to prevent users from accidently deleting multiple transactions at once, as once they're deleted they cannot be undeleted. I'll walk you through the steps to delete an expense transaction from your QuickBooks Online company: 

• Navigate to the Expenses menu, then select the Expenses tab.
• Find expense you want to delete.
• Click on the Action dropdown menu, then select Delete.
• Select Yes to confirm that you want to deletion.

The expense will then be removed from your accounts and reports, however you can still view a record of it within your Audit log. You can learn more about voiding and deleting transactions in these Community articles: 

• Enter and manage expenses in QuickBooks Online

• Void or delete transactions in QuickBooks Online

If there's anything else I can assist with don't hesitate to reach out! 

that sucks.