Matching of credit notes can reverse supplier tax reduction unless recipient amends returns, leading to additions and interest. Matching requires suppliers' reductions in output tax to be cross-checked with recipients' reductions in input tax; matched reductions are accepted and communicated. Discrepancies or duplications are communicated and, if unrectified, added to the supplier's output tax in subsequent returns. The supplier may reclaim additions if the recipient declares the credit note within the prescribed time. Interest is payable on amounts added from the date of the original claim until addition; accepted subsequent reductions permit refund of interest to the supplier via the electronic cash ledger, subject to the limit of interest paid by the recipient.