Hello there, someonehosed.

Thank you for posting here in the Community. I'm here to help provide information about using these two QuickBooks products.

The Self-Employed version is specifically designed to track expenses and mileage automatically. While in QuickBooks Online, you may need to attach the receipts into the transactions manually.

If you want to track mileage, you can use bills as an alternative. For the detailed steps of the process, I'm adding the article I recommend on this:

How to track mileage.

Please keep in touch with me here should you have any additional questions or concerns. The Community is always ready to help.