**Find the approved purchase order first.** Search purchase orders for the vendor and amount and note the exact PO number, including any prefix. Expected: one open PO matches the vendor, amount, and date range.

**Open the unmatched invoice or remittance record.** Check the PO reference field; it is blank, or it holds an internal request number instead of the PO number. Expected: the mismatch is visible in the reference field, not in the amounts.

**Enter the exact PO number.** Copy the number from the purchase order record rather than typing it from the supplier paperwork, which often truncates prefixes. Expected: the field validates and the vendor on the PO matches the vendor on the invoice.

**Re-run matching.** Trigger matching again and watch the status. Expected: the invoice moves from unmatched to matched, and any remaining hold names a different reason such as quantity or tax.

**Document supplier-submitted cases.** If the supplier sent remittance detail with no PO because none was issued, attach the approval or exception note to the record instead of adding a false reference. Success check: the record is matched or exception-approved, with the PO number or the exception visible in the audit history.