Suo moto registration: temporary GST registration may be imposed when a liable person fails to apply, triggering verification. Suo moto registration under Rule 16 allows a proper officer to grant temporary registration and issue FORM GST REG-12 when a person liable to registration has not applied; the temporary registration is effective from the date of that order. The registrant must apply formally within ninety days or within thirty days after an appellate order upholding liability; verification and certificate issuance follow rules 9 and 10, and the GST Identification Number assigned after verification is effective from the date of the temporary registration order.