Input tax credit entitlement requires invoice, receipt, tax payment and timely return; nonpayment can reverse credit to output liability. A registered person may claim input tax credit for business supplies if in possession of prescribed tax invoices or debit notes, has received the goods or services (including deemed receipt), the tax has been paid to Government (cash or credit utilisation) and the return has been filed; credit on goods received in instalments is available only after the final instalment. Nonpayment to supplier within the prescribed period converts availed credit into output liability with interest, subject to reclamation upon payment. Credit is barred where depreciation was claimed on the tax component of capital goods and is time limited by the September following the financial year or the annual return deadline.