Cancellation of GST registration requires electronic FORM GST REG-16 with stock and liability details within thirty days. A registered person (except those under rule 5 or with a Unique Identity Number under rule 10) seeking cancellation under section 29(1) must electronically file FORM GST REG-16 on the Common Portal or via a notified Facilitation Centre, providing details of inputs, semi finished and finished goods, capital goods held in stock on the cancellation date, liabilities and payments made, and may attach supporting documents; voluntary registrants cannot seek cancellation before a one year restriction from the effective date of registration.