The Bill-to-PO Matching feature is available to:
Current Bill Approvers
Bill Requesters
Bill Reviewers
Organisation Administrators
Purchase Order Requesters - if they were added by an Approver during the Matching procedure
Important note: Purchase Order Requesters will not be added as Bill Approvers if the Bill-to-PO Matching is performed during the Review step, regardless of the settings.
Also note that if Bill-to-PO Matching is used as a condition in the Review, Approval, or Auto-Approval matrix, a Bill's matched or unmatched status can determine which Reviewer or Approver the Bill is routed to, or whether it is automatically approved.
See How to add a Bill-to-PO Matching condition for Xero Bill approvals for details.