Goods on approval basis: transport on delivery challan with e way bill; invoice on delivery; inter state cases attract IGST. Goods moved for supply on approval basis may be transported on a delivery challan, with an e way bill where applicable, and the supplier may issue the tax invoice at the time of delivery once the supply is accepted. If goods carried from one State are supplied in another State, such transactions are inter state supplies and attract integrated tax under the IGST regime.