Highlights Aadhaar is a 12-digit unique identification number issued by the Unique Identification Authority of India It has now become one of the significant identification documents as it contains your demographic as well as biometric data New Delhi: Aadhaar is a 12-digit unique identification number issued by Unique Identification Authority of India (UIDAI) has now become one of the significant identification documents as it contains your demographic as well as biometric data. This card also includes your name, address, contact details, photo, and biometric details. Since Aadhaar card is one of the most important government identity proofs, you should keep it updated to avail all the benefits and services. To make any changes in the Aadhaar card, you should visit the UIDAI's official website for updating your details through the Self Service Update Portal (SSUP). You can also visit the nearest Aadhaar Enrolment Centre located in your area for the same.