Input tax credit entitlement conditioned on invoice possession and receipt of supplies, with payment-linked reversal consequences. Registered persons may claim input tax credit for business-use supplies only if they hold a tax invoice or prescribed document from a registered supplier, have received the goods or services (including deemed receipt), the tax has been paid to Government in cash or by allowable credit, and they have furnished the return under section 39; credit for instalments accrues on receipt of the last instalment. Failure to pay the supplier within the prescribed period triggers reversal of credit with interest, while credit is disallowed where depreciation on the tax component has been claimed. Claims are time-limited to the September return following the financial year or the annual return, whichever is earlier.