Input tax credit eligibility tied to prescribed documentary evidence and supplier reporting, and communication via prescribed GST forms. Input tax credit is claimable only on specified documents such as supplier invoices, debit notes, import assessment documents and Input Service Distributor documents that contain prescribed particulars; a reduced set of core invoice details may suffice if full particulars are absent. Credit is barred where tax is paid pursuant to orders confirming demands for fraud or willful suppression. Availability of credit for invoices or debit notes is additionally conditioned on supplier furnishing of outward supply details and communication of the corresponding input credit to the recipient through the prescribed electronic statement.