ISO/IEC 7812 · Modulo 10 Checksum · Zero Data Transmission

Credit Card Validator

Verify payment card checksums and inspect issuer identification numbers (IIN/BIN). Runs entirely within your browser memory to protect cardholder security.

Privacy Certified: Executed 100% locally in your browser memory. No digits are transmitted or logged.

Sandbox Test Cards:

Card Number (PAN)Visa

Cardholder Name

Expiry Date (MM/YY)

Visa

4532 0151 1283 0366

CardholderALEX MERCER

Expires12/28

Luhn Algorithm (ISO/IEC 7812 Mod 10) Verification

✓ CHECKSUM VALID

×24=8

×15=5

×23=6

×12=2

×20=0

×11=1

×25=1

×11=1

×21=2

×12=2

×28=7

×13=3

×20=0

×13=3

×26=3

×16=6

Computed Sum: 50 (50 mod 10 = 0)

Payment Card Mathematics: The Luhn Formula & Issuer Identification

How the Luhn Algorithm (Mod 10) Works

Created by IBM scientist Hans Peter Luhn in 1954 and codified as ISO/IEC 7812-1, the Luhn formula detects accidental transcription errors and typos:

Step 1: Starting from the rightmost check digit, double the value of every second digit moving leftwards.
Step 2: If doubling a number results in a two-digit integer ($> 9$), sum its individual digits (equivalent to subtracting 9, e.g., $8 \times 2 = 16 \rightarrow 1 + 6 = 7$).
Step 3: Sum all processed and un-doubled digits together.
Step 4: If the total sum modulo 10 equals 0 (sum mod 10 === 0), the sequence is mathematically valid.

Anatomy of the Primary Account Number (PAN)

A 16-digit credit card number is not randomly generated; it contains structured routing data:

Major Industry Identifier (MII): The first digit identifies the issuer industry (4 or 5 for banking/financial, 3 for travel/entertainment, 6 for merchandising).
Issuer Identification Number (IIN / BIN): The first 6 to 8 digits specify the exact issuing financial institution.
Individual Account Identifier: Digits 7 through 15 identify the individual customer account.
Check Digit: The final digit is computed via Luhn to guarantee integrity.

Security & PCI-DSS Compliance

A valid Luhn checksum verifies mathematical sequence integrity, but does not indicate whether an account possesses available credit or is in good standing. Verification of active funds requires an authorized payment processor executing a zero-dollar or pre-authorization gateway transaction over secure encrypted networks.