# Credit Card BIN Decoder

> Identify a card's network from its BIN and validate the number with Luhn.

- Page: https://decoder.tools/credit-card-bin-decoder
- Category: Identification & Serials
- Status: live, runs in the browser
- Last reviewed: 2026-10-23

A BIN decoder reads the first six to eight digits of a payment card number — the Bank Identification Number, formally the Issuer Identification Number — to identify the card network and issuer, and validates the full number with the Luhn check digit.

## Example

```text Input
4111111111111111
```

```text Output
Visa • 411111
Network: Visa
BIN / IIN: 411111
Luhn check: ✓ valid
```

## What is the Credit Card BIN Decoder?

Card numbers are structured, not random. The first digit is the Major Industry Identifier: 4 is Visa, 5 is Mastercard, 34 and 37 are American Express, 6 is Discover. The first six to eight digits together form the IIN, registered to a specific issuing bank and product. The digits after that are the account identifier, and the final digit is a Luhn check digit.

Luhn exists to catch keying errors, not fraud. It detects every single-digit mistake and almost every transposition of adjacent digits, so a mistyped card fails before a payment is ever attempted. It provides no security whatsoever — generating a Luhn-valid number is trivial, which is why validation is a usability feature and authorisation is the real check.

Everything here runs locally, which matters more for this tool than for most. A card number should never be transmitted to a third-party service for a lookup, and with this decoder it isn't: the digits you type stay in your browser.

## How to use the Credit Card BIN Decoder

1. Enter the card number — spaces and dashes are ignored.
2. Read the identified network and card type from the BIN.
3. Confirm the Luhn check passes; a failure means a typo, not a declined card.

## When to use it

- Debugging a payment form's client-side validation logic.
- Confirming that a test card number is well-formed before a sandbox run.
- Identifying which network a card belongs to from its opening digits.

## Credit Card BIN Decoder at a glance

| | |
|---|---|
| IIN / BIN | First 6–8 digits — identifies the issuer |
| Networks | 4 Visa · 51–55 Mastercard · 34/37 Amex · 6 Discover |
| Check digit | Last digit, Luhn (modulo 10) |
| Length | 13–19 digits; 16 typical, 15 for Amex |

## FAQ

### Is it safe to enter a card number here?

The number never leaves your browser — there is no network request and nothing is logged. Even so, for anything beyond a test card, prefer your issuer's own tooling; good habits around card data are worth keeping.

### What does the Luhn check actually prove?

Only that the digits are internally consistent, which catches typos and transpositions. It says nothing about whether the card exists, is active, or has funds — only an authorisation request answers that.

### Can a BIN identify the exact bank?

Often, from a BIN database. This decoder identifies the network and card type locally; naming the specific issuing bank requires a lookup table that would have to be queried remotely.

### Why are BINs moving from six to eight digits?

The six-digit space ran out. The industry moved to eight-digit IINs to create more room for issuers, so modern BIN identification uses the first eight digits.