how to add a parts (or taxable items) subtotal in the footer in quickbooks desktop

Good evening, louie.

I appreciate you turning to the QuickBooks Community for support. I'd be happy to provide some information.

QuickBooks Desktop provides a few different options for itemized sales tax on your forms. I recommend taking a look a this article in order to decide the best option for your business needs. 

If you would like to see additional options come available in future updates, I recommend leaving feedback by following the steps provided here. I hope this helps!

Feel free to reach back out if you have any other questions.