Companies involved in supply of goods with annual turnover of more than Rs.40 lakhs are required to register GST mandatorily. In addition to the turnover, If there is Interstate sale of goods its mandatory to register GST irrespective of the turnover Example - If a product is sold from Tamilnadu to Kerala, its mandatory to register GST for supply of goods through E-commerce and Companies involved in Supply of services with annual turnover of more than 20 lakhs are required to register GST mandatorily and it’s not required to register GST for interstate supply of services.