What is Aadhaar?

India introduced Aadhaar in a government initiative to provide Indians with a unique identification number. The purpose was to simplify access to public welfare systems by linking citizens’ identities with a unique 12-digit number. It would reduce the need for multiple documents, combat corruption and identity fraud. It was officially launched by the Unique Identification Authority of India (UIDAI) in 2009. 

Indian entrepreneur and the co-founder of Infosys, Nandan Nilekani, was appointed by the then-government to lead the Aadhaar project and became Chairman of UIDAI, a statutory body established under the Ministry of Electronics and Information Technology. The then-Finance Minister Pranab Mukherjee proposed the Aadhaar initiative in the 2009 Union Budget, the country’s annual budget presentation. 

The first Aadhaar card was issued in 2010 under then-Prime Minister Manmohan Singh while the legal framework, the National Identification Authority of India (NIAI) Bill, was introduced in December of the same year. In February 2012 the UIDAI launched an online verification system for Aadhaar. Banks, telecoms companies and government departments could input an Aadhaar number into the system to verify whether the individual was a resident of India. In November of that year an Aadhaar-linked direct benefit transfer (DBT) scheme was launched.

The biometric deduplication technology for Aadhaar is provided by consortium partners Neurotechnology and Tata Consultancy Services (TCS).

Challenges

In 2012 former High Court judge K.S. Puttaswamy, along with lawyer Parvesh Khanna, filed a Public Interest Litigation (PIL) against the government in the Supreme Court of India challenging Aadhaar’s legal basis. The petition pointed out that the National Identification Authority of India Bill 2010 was still pending and that the UIDAI was proceeding based only on an executive order issued on 28 January 2009, and was therefore violating privacy under Article 21 of the Constitution when collecting citizens’ biometric data. 

On 23 September 2013 the Supreme Court issued an interim order declaring that government services could not be denied to anyone who did not possess Aadhaar, as it was only voluntary to have an identity number, despite some official agencies requiring it for services and benefits. 

In 2014 on March 24 the Supreme Court made a significant ruling when it sanctioned the UIDAI from sharing any Aadhaar data without gaining the explicit consent of the individual. The same judgement advised agencies to revoke Aadhaar requirements to access benefits. That same month Nilekani resigned as UIDAI chairman to contest in Indian elections and was succeeded by 1981-batch Indian Administrative Service (IAS) Officer Vijay Madan. 

A 2018 Supreme Court ruling upheld the constitutionality of Aadhaar, but declared it could not be used for private sector interactions. Subsequent legislation changed the digital ID’s footing to allow its use with the private sector.

Financial inclusion

On 3 March 2016, the Aadhaar (Targeted Delivery of Financial and Other Subsidies, Benefits and Services) Bill was introduced in parliament as a money bill by Finance Minister Arun Jaitley and was passed about a week later. President’s assent arrived on March 25, officially making the Aadhaar Bill law. By early 2017, Aadhaar is made mandatory for welfare, pension and employment schemes, as well as for filing income tax returns.  

Programs such as the Public Distribution System (PDS) and LPG (Liquefied Petroleum Gas) scheme come to rely on Aadhaar for recipient authentication. By linking bank accounts with Aadhaar, formerly unbanked citizens (who numbered 233 million in 2015) were able to access financial services like DBT, pensions and subsidies. 

By July 2018 the UIDAI introduced Face Authentication to strengthen Aadhaar security although other biometrics, such as iris or fingerprints, were also enabled on devices for authentication. The system had been used for more than a billion biometric authentications, as of January, 2025.

Article Topics

Aadhaar  |  biometrics  |  digital ID  |  digital identity  |  government services  |  India