As per Rule 36(1) of CGST Rule, the input tax credit shall be availed by a registered person, including the Input Service Distributor, on the basis of any of the following documents [rule 1(1) of Input Tax Credit Rules].
a. An invoice issued by the supplier of goods or services or both in accordance with the provisions of section 31;
b. An invoice issued in accordance with the provisions of clause (f) of sub-section of section 31, subject to the payment of tax;
c. A debit note issued by a supplier in accordance with the provisions of section
d. A bill of entry or any similar document prescribed under the customs act, 1962 or rules made thereunder for the assessment of integrated tax on imports;
e. An input service distributor invoice or input service distributor credit note or any document issued by an input service distributor in accordance with the provisions of sub-rule (1) of rule 54.