I have a franchise business in which there is input service tax in 10 stores (like we pay telephone bill, maintenance charges, etc. for all 10 stores) and there is output service tax in 5 stores (consignment commission is received for 5 stores, rest 5 stores is on purchase sale agreement so no output service tax). can we adjust the entire input service tax for output service tax? is one to one relation necessary? there is centralised billing system through head office for all.