When creating a PO with line items that are not for a customer order that would later need journal entries to adjust, this can be done with Category GL assignment.
- Create a Category and assign a GL distribution account; ie. Office Supplies
- Add a non-inventory product to above category
When the PO invoice is created, the cost from the line item(s) for the category will be distributed to the assigned GL for that category. In the example below there were also an inventory item ($8) on the same PO that was distributed to the default Inventory GL.
This set up could also be used for inbound freight that you do not want to allocate to the product(s) landed cost. Add a non-inventory freight expense "product" and assign it to a category that has a freight expense GL account.