Aadhaar Checksum Validator

How Aadhaar Checksum Validator Works?

The Aadhaar Checksum Validator runs all 12 digits through the Verhoeff algorithm. The checksum passes when the final value is 0.

1. 1Remove spaces and confirm 12 digits that do not start with 0 or 1.
2. 2Reverse the digits.
3. 3Apply the Verhoeff permutation P[i mod 8] to each digit.
4. 4Combine the results with the D5 multiplication table.
5. 5Mark the number valid when the final value is 0.

Aadhaar Checksum Validator Formula

The Aadhaar formula is valid ⇔ D(…D(D(0, P₀(a₁)), P₁(a₂))…, P₁₁(a₁₂)) = 0, where aᵢ are the 12 digits read from the right.

c = 0
for i, a in enumerate(reversed(digits)): c = D[c][P[i mod 8][a]]
valid ⇔ c = 0

• D is the dihedral group D5 table.
• P is the Verhoeff permutation table.

Verhoeff check digit of 23412341234 = 6
Complete = 2341 2341 2346
Validation over 12 digits → c = 0 → valid

Aadhaar Checksum Validator Conversion Table

The Aadhaar validation table shows synthetic 12-digit numbers with their Verhoeff result.

All numbers are synthetic and generated for testing. Real Aadhaar numbers are personal data.

What is Aadhaar Checksum Validator?

An Aadhaar Checksum Validator is a tool that checks the Verhoeff check digit of a 12-digit Aadhaar number issued by the Unique Identification Authority of India (UIDAI).

Aadhaar numbers never start with 0 or 1. A valid checksum confirms correct typing only; UIDAI authentication confirms the identity.

What are the uses of Aadhaar Checksum Validator?

There are 3 main uses of the Aadhaar Checksum Validator, including KYC forms, data quality checks, and test data.

• KYC forms: Banks and telecoms catch typos before Aadhaar authentication.
• Data quality checks: Government and HR systems flag invalid numbers.
• Test data: Developers build synthetic Aadhaar-format numbers for testing.