16-digit Aadhaar to have four hidden numbers
"As far as people are concerned, there would only be a 12-digit number that would be relevant for their identification and use. However, we are making a provision of extra four digits that would be a post-fix for this 12-digit number for pin-based identification. So, UID will become a 16-digit number for our use and the database that we will maintain," Ram Sewak Sharma, Director General and Mission Director of the Unique Identification Authority of India (UIDAI), told Business Standard.
These four digits, which the authority terms a 'virtual number', will change as and when the resident changes his pin number or residence. The user, however, will only use the 12-digit number allotted to him.