How do I update/edit/change a purchase order (PO)?
Suppliers cannot directly make changes/edits/updates to a PO. Your customer can submit a change order with edits. The change order will have the same PO number but a new version number.
Please contact your customer directly to ask them to submit changes.
SAP Business Network for Procurement & Supply Chain > Transaction Documents > Transaction (Purchase Orders, Ship Notices & Goods Receipts)