New Delhi: The Supreme Court on Monday said the unique identification number - Aadhaar card - cannot be made mandatory for availing benefits under social welfare schemes.

This was stated by a bench of Chief Justice Jagdish Singh Khehar, Justice D.Y. Chandrachud and Justice Sanjay Kishan Kaul.

Senor counsel Shyam Divan had challenged a spare of orders issued by the government making Aadhaar mandatory to access benefits under various schemes.

Aadhaar, a 12 digit unique-identity number, is issued to all Indian residents based on their biometric and demographic data. The data is collected by the Unique Identification Authority of India (UIDAI).

UIDAI is a statutory authority established on 12 July 2016 by the Government of India, under the Ministry of Electronics and Information Technology, under the provisions of the Aadhaar Act 2016.

It is the world's largest biometric ID system, with over 1.123 billion enrolled members as of 28 February 2017 and as of this date, over 99% of Indians aged 18 and above had been enrolled in Aadhaar.

Chief Economist of World Bank Paul Romer described Aadhar as "the most sophisticated ID programme in world".

However, Aadhaar is not a proof of citizenship. It does not itself grant any rights to domicile in India.