Input tax credit eligibility: invoice, receipt, tax payment and return filing are required to claim and retain credit. Input tax credit is available to registered persons for tax on supplies used in business, provided they hold a tax invoice or prescribed document, have received the goods or services, the tax has been actually paid to the Government (cash or by credit utilisation), and the statutory return has been furnished. Credit on instalment deliveries is allowed after the last instalment. Failure to pay the supplier within the prescribed period (excluding reverse charge supplies) triggers addition of the credit to output liability with interest, though payment restores the credit. Credit is disallowed where depreciation was claimed on the tax component, and claims are time barred after the due return for the September month following the financial year or the annual return, whichever is earlier.