Service Tax Liability on Job Work

Business Auxiliary Service covers 'processing of goods for the client'. Further, it excludes processing that amounts to manufcature. Therefore, if the activity undertaken by the job worker amounts to manufacture, excise is leviable. Else, service tax is payable. 

B A S when you book a bill at that time you have to pay service tax in GTS / GTA at the time of payment.

on an other hand if you (job work material sender) principal manufacturer  & your job worker is also registered under central excise as an manufacturer both are exempted from service tex charges.if you principal manufacturer  is not reg excise , job worker will charge the rate of duty not service tax, & if job worker is not reg under excise nothing has to do.