Job work procedure: inputs and capital goods may be sent tax-free to job workers subject to conditions and return. Section 143 allows a registered principal to send inputs or capital goods to a job worker without tax subject to prescribed conditions; the principal must return or cause supply of those goods from the job worker's premises within prescribed periods or declare them deemed supplied. The principal must maintain accounts and declare the job worker's place as an additional place of business unless exceptions apply. Waste and scrap may be supplied by a registered job worker or by the principal if the job worker is unregistered, with tax payable. Input includes intermediate goods arising from processing.