Three-way matching compares the amounts, quantities, and prices recorded on a supplier invoice against the corresponding purchase order and receipt, and when an invoice line amount exceeds what the purchase order authorizes, a match exception is generated that must be resolved before the invoice can proceed to payment. The Official Workday Pro Procure-to-Pay Guide describes contacting the supplier to obtain a corrected invoice as the appropriate resolution when an invoice is billed at a higher amount than the agreed purchase order price, since the discrepancy reflects a billing error on the supplier's part rather than a system configuration issue. Option A is incorrect because adding the supplier to the portal addresses access and self-service capability, not a pricing discrepancy on a specific invoice. Option B is incorrect because creating a new match exception rule would alter system-wide tolerance configurations rather than resolve this individual transactional discrepancy, and is not an appropriate response to a one-off pricing error. Option C is incorrect because creating an additional receipt would misrepresent actual receiving activity unless additional goods were genuinely received, which is not indicated here.