The GST in India is considered one of the biggest reforms in indirect taxation. The essence of the GST system lies in providing a set-off for the input tax paid earlier by a registered supplier. The complete elimination of tax cascading and tax pyramiding is an attractive aspect of the GST system. Under the GST system, one can easily find out the entire tax element in the price because it equals the final tax paid by the ultimate customer. The study aims to identify the problems faced by retail merchants in GST implementation and return filing. 30 respondents were chosen from Iritty area through convenience sampling technique. The major findings where all retail merchant, have registered their businesses under Goods and Service Tax (GST). Majority did not encounter difficulties during the GST implementation and return filing. The major challenges faced during the GST implementation were software purchase, document requirements, and a lack of awareness about the law. Thus, it is concluded that adequate measures must be taken by the Govt to bring flexibility in the provision of GST and clearly issue notifications regarding GST.