Matching of credit notes requires reconciliation with recipient input tax reductions, adjustments, communications, interest and possible refunds. Suppliers' credit notes must be matched with recipients' corresponding reductions in input tax claims; matched reductions are accepted and communicated, while discrepancies or undeclared or duplicative reductions are notified and the discrepant amounts are added back to the supplier's output tax liability. Interest attaches to amounts added back from the date of the original claim until addition; if the recipient subsequently declares the credit note within the prescribed period, the supplier may reverse the addition and recover interest, limited to the interest paid by the recipient.