I have logged in today to complete my tax return for the previous year and all of my mileage has been deleted. this years mileage is still available but all of last years has gone! any ideas? Thanks

I appreciate you for bringing this to our attention, @jamesmayhew27-gm.

Let me share some ideas about missing previous mileage in QuickBooks Self-Employed.

If you're trying to check the trips, let's ensure to add the correct filter to show the previous year's mileage. Let me show you how:

1. Log in to your QBSE account.
2. Go to the Miles menu at the left panel.
3. Under Type, choose All.
4. Next to Type, select the previous year in the dropdown menu.
   
   

If the issue persists, we can perform some troubleshooting steps to fix this. There are times that the browser is full of frequently accessed page resources, which causes some errors or unusual responses. Let's start by accessing your account using a different or a private browser. You can use either of these keyboard shortcuts:

• Google Chrome: Ctrl + Shift + N
• Mozilla Firefox: Ctrl + Shift + P
• Microsoft Edge: Ctrl + Shift + P
• Safari: Command + Shift + N

If it works successfully, you'd want to clear your regular browser's cache to prevent any unexpected behavior. Also, you can use other compatible browsers in QBSE. 

If your issue has something to do with missing mileage deduction, I've found that we have an ongoing investigation about this. Rest assured that our product engineers are diligently working for a fix.

As a workaround, you can consider downloading the Tax Summary or Tax Details report. Please see the screenshot below for a visual representation. 

To ensure you'll get an update about the resolution status, I recommend contacting our Phone Support Team. This way, they can add your company to the list of affected users and provide this investigation number for easy tracking: INV-60395.

You can also read through this article to guide you on how to use the QuickBooks Self-Employed mobile app to trace your business miles automatically: Track mileage.

Keep in touch with me here if you need further assistance in managing your mileage in QuickBooks. I always got your back. Thanks for reaching out, and have a nice day!