Input Tax Credit eligibility requires supplier reporting and communication before recipient can claim credit under GST framework. Input Tax Credit under Section 16(2) requires prescribed documents (invoices, debit notes, bills of entry etc.) containing specified particulars, receipt of goods or services (including deemed receipt rules and contract specific constructs), supplier reporting of outward supplies and communication to recipients, actual payment of tax to the Government as required by statute, and filing of returns; Rule 36 enforces documentary conditions and bars credit where tax is confirmed as payable due to fraud, and procedural mechanisms link availment to supplier reporting and return based communication.