India Original explainer
Aadhaar is a 12-digit identity number from UIDAI — what it is, where it is used, and where it is not required.
Aadhaar is the identity number that most people in India now carry in their wallet or on their phone. It is a 12-digit number, issued to residents of India, and it is linked to a person's name, address, photograph, fingerprints and iris scans. Banks, government offices and many everyday services ask for it as proof of identity. Yet many people are unsure what Aadhaar actually proves, when it is compulsory, and when it is not. This guide explains Aadhaar in plain language, from how it started to how to use it safely.
Aadhaar is a 12-digit unique identification number. It is issued by the Unique Identification Authority of India, known as UIDAI. UIDAI was first set up in January 2009, and it became a statutory authority under the Aadhaar Act, 2016, on 12 July 2016. It works under the Ministry of Electronics and Information Technology. The first Aadhaar number was issued in September 2010, to a resident of Nandurbar in Maharashtra. By October 2024, more than 138 crore Aadhaar numbers had been issued, making it the world's largest biometric identity system.
Each number is linked to two kinds of information. Demographic details include your name, date of birth, gender, address and photograph. Biometric details include the fingerprints of all ten fingers and scans of both irises. Together, they are meant to make sure that one person gets only one Aadhaar number, and that the number cannot easily be given to someone else. The number itself is issued for life, although your details can be updated if they change.
Any resident of India can enrol for Aadhaar. A resident, for this purpose, is a person who has lived in India for 182 days or more in the 12 months before applying. You do not have to be an Indian citizen to get Aadhaar, and foreign nationals who meet the residence rule can also enrol. Children can enrol too. For a child below five years, no fingerprints or iris scan are taken, and the child's Aadhaar is linked to a parent's Aadhaar. The child's biometrics are taken later, when the child grows older.
Enrolment happens at an Aadhaar enrolment centre, where your details are recorded and your photograph, fingerprints and iris scans are taken. You will need to give proof of identity and proof of address, from the documents UIDAI accepts. After enrolment, you receive an enrolment slip with a number that lets you check the status of your application. Once the number is generated, you can download the Aadhaar letter online or get a printed copy. If you move house, change your name, or find a mistake, you can apply to update those details.
Aadhaar is mainly used in two ways: as proof of identity and address, and as a way to check that the person in front of an official is the same person the number belongs to. That check, called authentication, can use a fingerprint, an iris scan, a photograph, or a one-time password sent to the registered mobile number. Here are the most common uses.
In many of these cases, Aadhaar is one accepted option, not the only one. If an office insists on Aadhaar for something where the law does not make it compulsory, you can ask what other documents are accepted.
Aadhaar is proof of identity and residence, not proof of citizenship. Section 9 of the Aadhaar Act, 2016, says this clearly. Because Aadhaar is given to residents, including foreign nationals who have lived in India for 182 days or more, holding the number does not make a person an Indian citizen. It also does not, by itself, prove a person's date of birth or domicile. It cannot be used as a travel document, and it is not a substitute for a passport or a voter identity card when citizenship itself has to be proved.
In September 2018, a five-judge bench of the Supreme Court delivered its judgment in the Aadhaar case, Justice K.S. Puttaswamy (Retd.) v. Union of India. By a majority of four to one, the court upheld the constitutional validity of the Aadhaar Act. It said Aadhaar could be required for government subsidies and welfare benefits paid from public funds, because that helps make sure benefits reach the right people and reduces fraud.
At the same time, the court placed clear limits on mandatory linking. It struck down the rule that made it compulsory to link Aadhaar with bank accounts and mobile phone connections, and it struck down the provision that allowed private companies to demand Aadhaar authentication. In one line, the court's position was this: Aadhaar can be mandatory for welfare benefits, but it cannot be forced on people for bank accounts, mobile SIM cards, or private company services.
Your Aadhaar number is linked to your biometrics, so treat it with the same care as a bank password. Share a full copy only when it is genuinely needed, and use a masked copy or a virtual ID where that is accepted. Never share your one-time password with anyone, including a person who claims to be calling from a bank or a government office. If your Aadhaar details change, update them through an official enrolment centre or the UIDAI website.
This explainer was written by The Daily Short's desk from the sources listed above. It is general information, not professional advice. Spot an error? Tell us via the Contact page and we will correct it. Follow our official Instagram @the.daily.short.