You can hide the unit cost and total cost of products added to a purchase order (PO). This way, the PO PDF downloaded or opened from the PO email does not show the unit cost and total cost columns.
To hide the unit cost and total cost columns:
1/ Go to the PO Details view.
2/ Click the 3-dot menu next to the PO status, and then click "Hide pricing from supplier."
You can see the Unit Cost and Total Cost columns indicate that they are not shown in the PO PDF.
If you are creating multiple purchase orders at once, you can see the option to hide pricing in the left pane where you select the PO. Click the "Hide pricing for supplier" checkbox for the relevant PO.
You can set the ordering default for a supplier to hide the pricing on purchase orders in the Supplier Details modal.
Check out this article for more details.