Aadhaar Number Structure

An Aadhaar number is a 12-digit unique identifier with a specific format. Learn more about what is an Aadhaar number and its importance in India.

• Digits 1-11: Randomly generated numbers
• Digit 12: Checksum digit calculated using the Verhoeff algorithm

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. When you use our Aadhaar validator, it applies this algorithm to verify the checksum.

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 calculated using Verhoeff algorithm

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
• Implementing efficient KYC processes

Organizations implementing format validation can significantly reduce operational costs. Discover how businesses use Aadhaar validation to improve their operations.

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. For a step-by-step guide, see how to validate an Aadhaar number.

Privacy and Compliance

When working with Aadhaar numbers, it's important to understand the legal requirements and privacy considerations. Read our guide on privacy and legal considerations when using Aadhaar data to ensure your implementation is compliant with Indian data protection laws.