Input Service Distributor allocation of ITC: proportional distribution to attributable operational units based on state turnover. Where a one-to-one link between input services and recipients cannot be established, an Input Service Distributor must distribute Input Tax Credit only among recipients to whom the service is attributable and among operational units, apportioned in the ratio of each recipient's State or Union territory turnover during the period to the aggregate turnover of all attributable recipients, and subject to a ceiling that distributed credit not exceed the credit available for distribution.