Small Scale Industries (SSI) or Micro, Small and Medium Enterprises (MSME) can register themselves under the MSMED Act. It isn't necessary, but very beneficial to do so, as it only exists to offer benefits to those registered under it. These benefits include priority sector lending, excise and direct tax exemptions, capital investment subsidies and power tariff subsidies. To qualify as an MSME, manufacturing enterprises need to have investment of less than Rs. 10 crore in plants and machinery, while service enterprises must have no more than Rs. 5 crore invested in plant and machinery. If, at any time, you cross this investment limit, you need to cancel your registration under the MSMED Act.