Matching of credit notes ensures supplier output tax adjustments, communications on discrepancies, and restoration upon recipient correction. Section 43 requires prescribed matching of suppliers' credit notes with recipients' declared reductions in input tax credit and detection of duplicated claims. Accepted matches are communicated; where supplier reductions exceed recipient declarations or recipients fail to declare, discrepancies are communicated and, if unrectified, added to the supplier's output tax liability in the succeeding return. Duplications are added when found. Suppliers may reclaim such additions if the recipient later declares the credit note within the allowed return period. Interest is payable on added amounts and refundable to the supplier if the recipient's declaration leads to acceptance, subject to a cap.