Input tax credit entitlement requires invoice, receipt, tax payment and return filing, with reversal if recipient fails payment. A registered person may claim input tax credit for business use inputs only if in possession of a tax invoice or prescribed document, has received the goods or services (including deemed receipt on delivery to a directed recipient), the tax on the supply has actually been paid to government, and the claimant has filed the required return. Credit on goods received in instalments is allowed when the last instalment is received. Failure by a recipient to pay the supplier within the prescribed period triggers addition of the credit to output liability with interest, but credit can be availed upon payment. Depreciation claimed on the tax component of capital goods disallows that credit, and claims are subject to a statutory time bar tied to the year end return.