Understanding Aadhaar Number Format
December 24, 2024

Aadhaar Number Structure

An Aadhaar number is a 12-digit unique identifier with a specific format:

  • Digits 1-11: Randomly generated numbers
  • Digit 12: Checksum digit

The Verhoeff Algorithm

The Verhoeff algorithm is used to generate and validate the checksum digit. This algorithm helps detect common errors in the Aadhaar number, such as single-digit mistakes and transposition errors.

Key Features of the Aadhaar Format

  • Always 12 digits long
  • First digit is never zero
  • No alphabets or special characters
  • Last digit is a checksum

Why Format Matters

Understanding the Aadhaar number format is crucial for:

  • Developing robust validation systems
  • Ensuring data integrity in databases
  • Preventing fraudulent use of fake numbers

Using Our Validator

Our Aadhaar Check tool uses this understanding of the Aadhaar format to provide quick and accurate validation. It checks both the format and the checksum to ensure the number's validity.