Input tax credit entitlement requires invoice, receipt, tax payment and return filing before statutory time limits. Every registered person may claim input tax credit for business-use supplies, provided they hold a tax invoice or prescribed document from a registered supplier, have received the goods or services, the tax on the supply has been paid to Government, and the relevant return under section 39 has been furnished. Instalment receipts permit credit only after the last instalment is received. Failure to pay the supplier within the prescribed period requires reversal of credit with interest, and credit is disallowed where depreciation on the tax component has been claimed. Claims are time barred after the return due for the month of September following the financial year or on annual return filing, whichever is earlier.