A Village Woman, a 12-Digit Number, and the World's Biggest ID Project

On 29 September 2010, in the small tribal village of Tembhli in Nandurbar district, Maharashtra, a woman named Ranjana Sonawane received a 12-digit number. It was the very first Aadhaar number ever issued ^[3].

Until that day, like millions of Indians, she had no easy way to prove who she was. No passport. No driving licence. Sometimes not even a birth certificate. Without proof of identity, it was hard to open a bank account, get a mobile phone connection or receive government benefits meant for her.

Fifteen years later, Aadhaar has been issued to well over a billion people, making it the largest biometric digital identity programme in the world ^[2][3].

The problem of the invisible citizen

For decades, India faced a basic problem. A huge number of people, especially the poor, migrants and those in remote villages, had no reliable identity document. Different government departments issued different cards, and none of them talked to each other.

This created two serious issues. First, genuine people were often left out of welfare schemes because they could not prove who they were. Second, fake and duplicate names on lists meant that money meant for the poor sometimes went to people who did not exist ^[3].

The idea behind Aadhaar was to give every resident a single, unique number, linked to their fingerprints, iris scans and photograph, that could be checked anywhere in the country.

The word aadhaar itself means “foundation” or “support” in Hindi. The name captured the goal: a foundation on which other services could be built.

Building it from scratch

The Unique Identification Authority of India (UIDAI) was set up in 2009. Technology entrepreneur Nandan Nilekani, a co-founder of Infosys, was appointed its first chairman, with the rank of a cabinet minister ^[3].

The task was enormous. Engineers had to build a system that could store the details of over a billion people, compare each new enrolment against everyone already enrolled to make sure no one got two numbers, and do all of this reliably, securely and cheaply.

Enrolment centres were set up in post offices, banks, schools and government buildings across the country. Teams took enrolment kits to remote villages, hill regions and forest areas. People queued to have their fingerprints and irises scanned and their photographs taken. Enrolment was free ^[3].

A key design choice was that Aadhaar is a number, not a card with special powers. It holds only basic details: name, date of birth, gender and address, along with the biometric data. It does not record a person’s religion, caste, income or health ^[3].

Checking identity in seconds

What makes Aadhaar useful is not just having a number, but being able to confirm it quickly. This is called authentication.

When a person wants to prove who they are, for example at a bank or a ration shop, they can give their Aadhaar number and place a finger on a scanner, look into an iris reader, receive a one-time password on their phone, or, more recently, use face authentication. The system replies with a simple “yes” or “no” to confirm whether the person is who they claim to be.

The scale is staggering. By the end of April 2025, Aadhaar had handled more than 150 billion authentication transactions since it began. In April 2025 alone, there were nearly 210 crore authentications, about 8 per cent more than a year earlier ^[1].

What Aadhaar made possible

Aadhaar became a building block for many services that followed.

• Direct Benefit Transfer. Government subsidies and payments, such as for cooking gas, scholarships, pensions and farmer support, can be sent straight into the bank accounts of the right people. This has helped cut out middlemen and remove fake beneficiaries ^[3].
• Bank accounts for all. Along with simplified rules, Aadhaar helped crores of people open bank accounts for the first time.
• Instant e-KYC. Banks, telecom companies and other service providers can verify customers in minutes rather than days, which lowers costs and makes services easier to access ^[1].
• Digital payments. By making it easier to open accounts and link them to phones, Aadhaar helped lay the ground for the explosion of digital payments through UPI.
• Ration and pensions anywhere. Migrant workers can use their identity to access food rations in other states under the “One Nation, One Ration Card” scheme.

Together, Aadhaar, bank accounts, mobile phones and UPI are often described as India’s digital public infrastructure, a model that other countries have studied closely.

Debate and safeguards

Aadhaar has also been the subject of strong public debate, particularly about privacy and how far it should be required. These concerns reached the Supreme Court of India.

In a landmark 2017 judgement, the Court declared privacy to be a fundamental right. In 2018, it upheld the Aadhaar programme as constitutionally valid, but placed limits on its use. For example, it ruled that private companies could not insist on Aadhaar in many situations, and that it could not be made compulsory for things like school admissions ^[3].

UIDAI has since added further privacy features, such as virtual IDs that can be shared instead of the real number, and the ability for people to lock their biometric data. Debate continues, as it should in a democracy, about striking the right balance between convenience and privacy.

Updating and protecting your Aadhaar

UIDAI encourages people to keep their Aadhaar details up to date, especially their address and mobile number, and to update their biometrics as children grow older ^[2]. Updates can be done at Aadhaar centres, and some changes can be made online.

Citizens are also advised to protect their Aadhaar like any other important document: avoid sharing the full number unnecessarily, use the masked or virtual ID where possible, and never share one-time passwords with strangers.

Why Aadhaar makes India proud

Building a reliable identity system for more than a billion people, across languages, regions, mountains and deserts, is something no country had attempted before. India did it in a little over a decade.

For many Indians at the bottom of the ladder, Aadhaar was the first official document that truly belonged to them. It helped them open bank accounts, receive benefits directly and take part in the digital economy.

It all began in a small village in Maharashtra, with one woman receiving one number. From that modest start grew one of the most ambitious technology projects in history.