Generally GST is payable by taxable person who supplies goods or gives service or both- Section 9(1) of CGST Act & Section 5(1) of IGST Act. However there are few exceptions to this aka, GST payable by recipient of Goods or Service or both- Section 9(3) or 9(4) of CGST Act or Section 5(3) or 5(4) of IGST Act. This means that receiver of goods/service will discharge the duty of GST payment of supplier of goods/service.
It is mandatory to pass on the benefit due to reduction in rate of tax or from input tax credit to the consumer as an anti-profiteering measure.
Section 10 of CGST act provides for a simplified composition scheme. This composition scheme would be available for business units whose aggregate turnover of supply of goods in a financial year does not exceed Rs. 75 lakhs. (GST Council meeting on 11-06-2017).