The Constitution (122nd Amendment)(GST) Bill, 2014 was passed by Rajya Sabha on 3rd August 2016 and by Lok Sabha on 8th August, 2016 (to confirm to the changes suggested by Rajya Sabha). The Bill was then ratified by more than half of States across the country and received the Presidents assent on 8th September 2016 thereby becoming The Constitution (101st Amendment) Act, 2016.
As per Section 1(2) of the Constitution (101st Amendment) Act, 2016 different dates may be provided by Central Government when the provisions of this Act would come into force. Accordingly, Central Government has notified 12th September 2016 as the date on which the provisions of Section 12 of the said Act will come into force and 16th September 2016 as the date on which rest of the provisions (1-20 except 12) will come into force.
MINISTRY OF FINANCE
(Department of Revenue)
New Delhi, the 10th September, 2016
S.O. 2915(E).—In exercise of the powers conferred by sub-section (2) of section 1 of the Constitution (One Hundred and First Amendment) Act, 2016, the Central Government hereby appoints the 12th day of September, 2016 as the date on which the provisions of section 12 of the said Act shall come into force.
[F. No. 31011/09/2015-SO (ST)]
UDAI SINGH KUMAWAT, Jt. Secy.
Read Relevant Provisions of sub-section (2) of section 1 and section 12 of Constitution (One Hundred and First Amendment) Act, 2016 at the following link :-