This doctoral research by Prem Singh, under the supervision of Prof. (Dr.) Satvinder Kaur at the University of Delhi, critically evaluates the impact and challenges of implementing the Goods and Services Tax (GST) in India, with a special focus on Delhi’s dynamic economy. As one of India’s key commercial hubs, Delhi presents a microcosm of diverse business activities across manufacturing, services, and retail sectors. The study employs a quantitative research design using SPSS-based statistical analyses to assess GST’s effects on compliance costs, operational efficiency, consumer behaviour, and the ease of doing business. Findings reveal that while GST has unified the tax regime and improved transparency, small and medium enterprises continue to face significant compliance and technological challenges. The thesis recommends simplifying return procedures, stabilising tax rates, and providing digital support for SMEs. Ultimately, it underscores that a more inclusive, streamlined GST can foster equitable growth and economic efficiency.