Glossary · Finance & Payments

Aadhaar

Aadhaar is a 12-digit identity number issued to residents of India by the UIDAI, linked to demographic and biometric data and used for identity verification.

Updated October 6, 2026

Aadhaar is a 12-digit unique identification number issued by the Unique Identification Authority of India (UIDAI) to residents of India. It is linked to demographic details (name, date of birth, address) and biometric data (fingerprints, iris scan and photograph) held in a central database.

Why it matters

Aadhaar acts as a digital identity layer. Service providers can authenticate a person by sending the number with an OTP or biometric to UIDAI and getting a yes/no answer, or retrieve limited details with consent through e-KYC. This allowed banks, telecom firms and fintech apps to onboard people without paper copies. Its use is governed by Indian law and court rulings, and which services may require or accept it has changed over time.

Example

A fintech app asks for an Aadhaar number, sends an OTP to the mobile number registered with UIDAI, and receives a verified name and address on success. Many apps use a masked version in which only the last four digits are shown, to limit exposure of the full number.

Common misconceptions

  • Aadhaar is an identity number, not proof of citizenship or a bank account.
  • It is not the same as a PAN card, which is a tax identifier.
  • Sharing the full number casually is risky. Prefer masked copies where accepted.

Rules vary by country; this entry is a definition only and not legal advice.

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