UIDAI (Aadhaar)

UIDAI issues Aadhaar, India’s unique identity number. It is the world’s largest biometric identity system. Over 130 crore residents hold an Aadhaar number. This lesson covers the Authority itself: how it began, how it works, the Supreme Court case that set its limits, and what changed in 2026.

1Chapter 1: What UIDAI Is

Must Know

From office to Authority

• UIDAI is the Unique Identification Authority of India. It issues Aadhaar numbers to residents.
• It began in January 2009 as an attached office under the Planning Commission.
• Nandan Nilekani was its first Chairman.
• The Aadhaar Act, 2016 gave it statutory status. The Act came into force on 12 July 2016.
• UIDAI now works under the Ministry of Electronics and Information Technology (MeitY).
• Read more: The Planning Commission of India.

Who runs it

• A Chairperson, two part-time Members and a Chief Executive Officer (CEO).
• The CEO is also Member-Secretary, the administrative head and legal representative.
• See the UIDAI organisational structure.

What Aadhaar is for

• It was designed to remove duplicate and fake identities from welfare delivery.
• Biometric checks make verification easy and cheap.
• It mainly authenticates identity for subsidies, pensions and scholarships paid from the Consolidated Fund of India.
• It has also become the default KYC for bank accounts, SIM cards and income tax returns.

2Chapter 2: How Authentication Works

Must Know

Yes or no

• Enrolment collects fingerprints, iris scans and a photograph.
• By law, enrolment is voluntary.
• Your number and a fingerprint, iris scan or OTP are matched against the Central Identities Data Repository (CIDR).
• The reply is only “Yes” or “No”.
• It never sends back your name, address or photo.
• Data is encrypted at enrolment and decrypted only inside the CIDR, with 256-bit encryption and strict access controls.

Open APIs

• Aadhaar’s open APIs let it be built into any electronic device.
• They also make online iris authentication possible.
• Read more: Aadhaar’s Open APIs.

Numbers can be switched off

• The Issuing Authority can deactivate or omit a number, for reasons such as false enrolment.
• UIDAI has also deactivated over 2 crore numbers linked to deceased people.

3Chapter 3: The 2018 Supreme Court Case

Good to Know

What was decided

• The case is Justice K.S. Puttaswamy (Retd.) v. Union of India, decided on 26 September 2018.
• By a 4:1 majority the Court upheld the Aadhaar Act’s core validity.
• It struck down Section 57.
• That section had let private firms, like banks and telecom companies, demand Aadhaar authentication.
• After it, no bank or school board could make Aadhaar compulsory for its own services.
• The Court also capped metadata storage at six months, not three.

Two different Puttaswamy cases

• This 2018 case is distinct from the 2017 right-to-privacy judgment.
• Both carry the Puttaswamy name.
• Read more: Right to Privacy and the Puttaswamy Judgment and The Supreme Court.

The Tribune story

• On 3 January 2018 The Tribune reported buying access to a portal that could pull up any holder’s details.
• The price was ₹500, paid through Paytm, and it took about ten minutes.
• The racket traced back to WhatsApp groups targeting village-level enterprise operators hired for enrolment.
• UIDAI filed an FIR against the journalist and the newspaper, not against the racket. This drew heavy criticism over press freedom.
• The episode showed why enforceable data-protection limits mattered.

4Chapter 4: Where Aadhaar Is Mandatory

Good to Know

Three cases

• Benefits paid from the Consolidated Fund of India: mandatory under Section 7.
• Private services such as insurance: not mandatory. A 2019 IRDAI advisory followed the Puttaswamy ruling.
• Proof of citizenship: not valid.

What DBT saved

• The government credits Aadhaar-linked Direct Benefit Transfer (DBT) with saving ₹3.48 lakh crore.
• It did so by cutting ghost and duplicate beneficiaries from welfare rolls.
• Coverage grew from about 11 crore to 176 crore beneficiaries.
• Subsidy spending’s share of government spending reportedly fell from about 16% to 9%.
• This is a government estimate, not independently audited.

5Chapter 5: UIDAI in 2026

Great to Know

The Aadhaar app, Pehchaan

• On 28 January 2026, UIDAI Day, a new Aadhaar app was launched in New Delhi.
• Minister of State Jitin Prasada launched it. (Source: Akashvani News.)
• It replaces the older mAadhaar app.
• It adds QR-based selective data sharing, face authentication, offline verification and family profiles.
• By 22 June 2026 downloads crossed 31 million.
• Nearly 40 lakh people had updated their mobile number and almost 8.5 lakh their address through it. (Source: PIB.)

Free updates for children

• UIDAI waived charges for children’s Mandatory Biometric Updates, ages 5 to 17, up to 30 September 2026. (Source: Akashvani News.)
• A child’s biometrics change as they grow. The update keeps authentication working for exams like NEET, JEE and CUET.
• By February 2026 UIDAI had completed over 1 crore such updates. (Source: Akashvani News.)
• Reports say a fee of ₹125 applies from 1 October. Check UIDAI for any new extension.

Leadership and scale

• Saurabh Vijay, an IAS officer, took charge as CEO on 18 May 2026.
• Economist Neelkanth Mishra held the part-time Chairperson post. He was named India’s World Bank Executive Director in June 2026.
• Read more: Neelkanth Mishra, World Bank Executive Director.
• About 134 crore Aadhaar numbers are active. That is roughly 99% of India’s adult population.
• The World Bank’s Chief Economist once called it the most sophisticated ID programme in the world.
• UIDAI’s challenge now is keeping the database accurate at huge scale.

6Chapter 6: Exam Traps

Great to Know

Three traps

• Metadata limit is six months, not three.
• Aadhaar is not mandatory for insurance.
• Aadhaar is not proof of citizenship, and numbers can be deactivated.
• Related: TRAI: Telecom Regulatory Authority of India.

7Previous Year Questions

Exam angle: real questions on this topic.

Quick Q&A

• UIDAI created? January 2009.
• Act in force? 12 July 2016.
• Verdict majority? 4:1.
• Metadata limit? Six months.
• Parent ministry? MeitY.