Input tax credit matching requires reconciliation with supplier returns and leads to adjustments in output liability. Matching of a recipient's inward-supply details with the supplier's outward returns, integrated tax on imports, and duplication checks governs acceptance of input tax credit; matched claims are finally accepted and communicated. Discrepancies where recipient claims exceed supplier-declared tax or are undeclared are communicated to both parties, and unrectified discrepancies or duplicated claims are added to the recipient's output tax liability and attract interest until corrected. Subsequent supplier declaration within the prescribed period permits reduction of the added amount and refund of interest to the recipient's electronic cash ledger subject to prescribed limits; improper reductions are re-added with interest.