How to Delete Backorder Purchase Orders
1. Checkmark both Non-Parts PO and Non-Parts PO Complete

2. Save
RESULT: The Purchase Order will show as "Closed".

3. Reopen
RESULT: The Delete option will become available.

4. Delete

Related Articles:
Creating a Purchase Order from an Invoice / Repair Order
Closing a Non-Parts Purchase Order
Receiving a Purchase Order and Creating a Back Order Purchase Order