Matching of credit notes: supplier reductions accepted only when recipient declares corresponding input tax credit in return. Every supplier credit note must be matched to a corresponding reduction in the recipient's input tax credit in the same or a subsequent valid return and checked for duplication. Matched reductions are accepted and communicated; discrepancies where supplier reductions exceed recipient declarations are communicated and, if not rectified in the specified return, added to the supplier's output tax liability. Duplicative reductions are added back. Added amounts attract interest from the date of claim until addition; if the recipient later declares the credit within the prescribed time, the supplier may reverse the addition and obtain refunded interest credited to the electronic cash ledger, limited to the interest paid by the recipient.