What is a BIN Number? Complete Guide

A BIN (Bank Identification Number) is the first 6 to 8 digits of a payment card number. It identifies the institution that issued the card and provides valuable information about the card type, brand, and country of origin.

Understanding BIN Structure

Payment card numbers follow a standardized format defined by ISO/IEC 7812:

4147 2012 3456 7890
^^^^
BIN (Bank Identification Number)

The BIN consists of:

• First digit: Major Industry Identifier (MII)
• First 6 digits: Traditional BIN
• First 8 digits: Extended BIN (increasingly common)

Major Industry Identifiers

The first digit indicates the card’s industry:

• 1, 2: Airlines
• 3: Travel and entertainment (e.g., American Express)
• 4: Banking and financial (e.g., Visa)
• 5: Banking and financial (e.g., Mastercard)
• 6: Merchandising and banking
• 7: Petroleum
• 8: Healthcare and telecommunications
• 9: Government and other

What Information Does a BIN Provide?

A BIN lookup reveals:

Card Brand

• Visa, Mastercard, American Express, Discover, etc.

Card Type

• Credit, debit, or prepaid

Card Level

• Classic, Gold, Platinum, Business, etc.

Issuing Bank

• The financial institution that issued the card

Country of Issuance

• Where the card was issued (not necessarily the cardholder’s location)

Additional Attributes

• Commercial vs. consumer
• Prepaid status
• Corporate card indicator

Why BINs Matter

Fraud Prevention

BIN lookup helps detect suspicious transactions:

• Mismatched billing country vs. card country
• High-risk BIN ranges
• Prepaid cards on restricted merchants
• Card type inconsistencies

Payment Routing

Optimize transaction routing based on:

• Card brand for processor selection
• Domestic vs. international cards
• Card type for appropriate handling

User Experience

Enhance checkout flows:

• Auto-detect card type as user types
• Display correct card icon
• Validate card format before submission
• Pre-fill country information

Compliance

Meet regulatory requirements:

• AML/KYC verification
• Country-based restrictions
• Card type restrictions
• Risk assessment

The Transition to 8-Digit BINs

Historically, BINs were 6 digits. Due to the growing number of card issuers, the industry is transitioning to 8-digit BINs:

Timeline

• April 2022: Mastercard began issuing 8-digit BINs
• 2024-2026: Industry-wide migration
• Future: 6-digit BINs will become obsolete

Impact on Developers

Systems must support both 6 and 8-digit BINs:

// Bad - assumes 6 digits
const bin = cardNumber.substring(0, 6);

// Good - supports 6-8 digits
const bin = cardNumber.substring(0, 8);

BIN vs IIN: What’s the Difference?

BIN (Bank Identification Number) and IIN (Issuer Identification Number) are synonyms. The industry is gradually shifting to “IIN” to reflect that issuers aren’t always banks, but “BIN” remains widely used.

Using BinLookupAPI

Our API makes BIN lookup simple:

curl -X GET "https://api.binlookupapi.com/v1/414720" \
     -H "Authorization: Bearer YOUR_API_KEY"

Response:

{
  "bin": "414720",
  "brand": "Visa",
  "type": "credit",
  "bank": {
    "name": "JPMorgan Chase"
  },
  "country": {
    "name": "United States",
    "code": "US"
  }
}

Conclusion

BIN numbers are fundamental to modern payment processing. Whether you’re building fraud prevention systems, optimizing payment routing, or enhancing user experience, understanding and utilizing BIN data is essential.

Ready to integrate BIN lookup into your application? Get started with a free API key.

Related Articles

• How to Use BIN Lookup for Fraud Prevention
• The Transition to 8-Digit BINs: What Developers Need to Know
• BIN Lookup API Integration Tutorial