Hello @Question878,
Thank you for posting here in the Community. Let me share some clarification about deleting employees in QuickBooks Online.
Currently, an option or ability to Unbill by batch is unavailable. As of now, the only option is to do it individually for each transaction.
I appreciate your input about being able to perform the process in a much easier way. We'll continue to update the features in QuickBooks Online, and this preference might be available in the future.
While we assess this, I suggest you visit our QuickBooks Blog to stay updated with all the changes with the product.
For additional reference, you can use the following article to learn more about deleting employee information in QuickBooks: Delete an employee's profile from payroll.
Feel free to let me know if you have any other questions about your old employees. I'll be right here to support you.