Input tax credit distribution by Input Service Distributor: prescribed-document allocation and pro rata turnover-based sharing among recipients. Input Service Distributors must allocate input tax credit by issuing prescribed documents; distributions cannot exceed available credit and credits attributable to a recipient must be given only to that recipient. Credits attributable to multiple recipients are allocated pro rata based on each recipient's turnover in the relevant period relative to the aggregate turnover of all operational recipients. The provision defines the relevant period for turnover comparison, identifies a recipient of credit as a supplier sharing the distributor's Permanent Account Number, and specifies how 'turnover' is to be measured for distribution.