the question of WCT arises only in the cases of contractors.Whenever in a contract both labour as well as material component is included in the invoice and the contract between the contractor and contracte does'nt bifurcate the amount of material and labour so it is not possible to assign the separate value for VAT and service Tax. therefore WCT is charged to the full value.
Therefore the following conditions are pre-requisite of charging WCT.
(1) Contract Work
(2) Contractor transfer some material along with his services
(3) Contract between the parties does'nt bifurcate the services and material amount
hence it can be said that WCT is a subsitution of VAT and Service Tax.