GST registration in India is required for businesses with annual turnovers above ₹20-40 lakhs (limits vary by state and business type) or interstate trading. It helps businesses to collect and recover GST on sales and purchases. The process is completed online via the GST portal by uploading crucial papers such as PAN, Aadhaar, and business proof. Once registered, companies gain a unique GSTIN, which guarantees tax compliance and access input tax credit benefits.