A purchase order line (POL) can only be deleted if it has one of the following statuses:
In Review
Packaging (Automatic or Manual)
Deferred or Canceled
A POL cannot be deleted if:
It’s part of a purchase order that’s already been sent to the vendor. (If the order hasn’t been sent yet, you can take the POL off the order and then delete it.)
It’s the main POL on an order where something has already been received or activated—even if the POL still shows as “in review.”
It’s linked to an invoice.
If you can't delete a POL, you may be able to cancel or reopen it so that it can be deleted: