GST enrolment: existing taxpayers must validate contact details, provide statutory identifiers, upload documents, and digitally sign enrollment. Enrolment requires validation of identity and business data including PAN and legacy registrations, provision of contact details and principal/additional place of business information, upload of constitution and place-of-business proof, bank account and photographs, Aadhaar consent and system validation of PAN/Aadhaar/DIN/CIN/LLPIN, authorisation for each signatory with supporting resolution/declaration, and mandatory electronic signing appropriate to the applicant type to obtain provisional registration and an ARN.