The Supreme Court on Thursday reserved its ruling on several petitions challenging the constitutional validity of Aadhaar and its enabling 2016 law.
The judgment was reserved after a series of hearing in 38 days over four months.
A five-judge constitution bench headed by Chief Justice Dipak Misra directed all the parties concerned to file their written submissions to put forth their case.
A battery of lawyers, including Attorney General K K Venugopal, who represented the Centre and senior advocates like Kapil Sibal, P Chidambaram, Rakesh Dwivedi, Shyam Divan, Arvind Datar, Rakesh Dwivedi had appeared for various parties.
The constitution bench also comprised Justices A K Sikri, A M Khanwilkar, D Y Chandrachud and Ashok Bhushan.
During the arguments spread over four months, the Centre had strongly defended its decision to seed Aadhaar numbers with mobile phones, telling the top court that it could have been hauled up for contempt if the verification of mobile users was not undertaken by it.
However, the court had said that the government had misinterpreted its order and used it as a "tool" to make Aadhaar mandatory for mobile users.
Former Karnataka High Court judge Justice K S Puttaswamy and other petitioners had challenged the constitutional validity of Aadhaar.
The court had also not agreed with the government's contention that the Aadhaar law was correctly termed as a Money Bill by the Lok Sabha Speaker as it dealt with "targeted delivery of subsidies" for which funds came from the Consolidated Fund of India.