Matching of credit notes ensures output tax reductions hinge on corresponding recipient input tax declarations, with add-backs and interest where discrepant. Matching of supplier credit notes with recipients' reductions in input tax credit is required; successful matches are accepted and communicated. Discrepancies where supplier reductions exceed recipient declarations, or undeclared credit notes, are communicated to both parties and, if unrectified within the prescribed month, added back to the supplier's output tax in the next return. Duplicate reduction claims are added back when communicated. Suppliers subject to additions pay interest from the date of the original claim until addition; if the recipient subsequently declares the credit note within the specified period, the supplier may reduce the added amount and receive an interest refund to the electronic cash ledger, limited to the interest paid by the recipient.