Input tax credit framework clarifies eligibility, apportionment, reversal, redistribution, and transfer rules affecting claim availability and compliance. The Handbook governs input tax credit (ITC), defining eligibility and documentary conditions for claiming ITC, procedures for apportionment and identification of blocked credits, availability in special circumstances, job work treatment, distribution by Input Service Distributors and recovery for excess distribution, reversal and re availment mechanisms for non payment by recipients or suppliers, determination and reversal methods for inputs and capital goods, and transfer of credit on business reorganisation, with specified restrictions and special case reversal rules.