Compulsory registration mandates specified suppliers and intermediaries to obtain GST registration regardless of turnover thresholds. Notwithstanding general registration provisions, specified categories of persons are mandatorily required to obtain registration under the Act. This includes persons making inter State supplies, casual and non resident taxable persons, persons liable to pay tax under reverse charge or specified tax provisions, persons required to deduct tax, agents or persons supplying on behalf of others, Input Service Distributors, electronic commerce operators, and suppliers of online information and database access or retrieval services from outside India to unregistered recipients; the Government may notify additional classes on the Council's recommendation.