Businesses with an annual turnover below ₹40 lakhs (₹20 lakhs for service providers) are exempt from GST registration. However, in special category states, the limit is ₹20 lakhs for goods and ₹10 lakhs for services. Beyond this, GST registration in Chennai is mandatory. For seamless online GST registration in Chennai, consult experts like Solubilis for hassle-free compliance and filings.