Rule-17 of CGST Rules 2017
17. Assignment of Unique Identity Number to certain special entities.- (1) Every person required to be granted a Unique Identity Number in accordance with the provisions of sub- section (9) of section 25 may submit an application electronically in FORM GST REG- 13, duly signed or verified through electronic verification code, in the manner specified in rule 8 at the common portal, either directly or through a Facilitation Centre notified by the Commissioner.
(2) The proper officer may, upon submission of an application in FORM GST REG-13 or after filling up the said form, assign a Unique Identity Number to the said person and issue a certificate in FORM GST REG-06 within a period of three working days from the date of the submission of the application.