BIN/IIN lookup: the card prefix ranges and how to look one up (2026)

TL;DR — A card’s first digits — the BIN (Bank Identification Number) / IIN (Issuer Identification Number) — identify the network and the issuer. You can read the network straight off the prefix ranges (table below). The issuer/bank/country needs a BIN database — there’s no formula for it. This page gives you the IIN range table, the 6-vs-8-digit caveat, and the three ways to look a BIN up (by hand, by site/API, programmatically).

Background reading on this blog: why a 6-digit BIN is now ambiguous and the story behind binlist.net and iinlist.com.

What a BIN/IIN is

The card number (PAN, primary account number) is structured: the leading digits are the IIN, identifying the issuing institution and network; the rest is the individual account number, with a final Luhn check digit. “BIN” is the everyday industry word; “IIN” is the formal term in ISO/IEC 7812. The IIN was 6 digits for decades and has been expanded to 8 for most networks — see the 8-digit post.

IIN prefix ranges by network

What you can determine from the prefix alone — which network issued the card:

Notes: ranges can overlap at the edges (e.g. some 62 UnionPay vs 622126–622925 Discover co-badging), and 50/56–69 for Maestro is broad and collides with others — which is exactly why issuer-level resolution needs a database, not a prefix rule.

What you cannot tell from the prefix

There is no formula that turns a prefix into a bank name, country, or debit/credit flag. That mapping lives in a maintained BIN database built from network bulletins and observed cards. So:

• Network → readable from the table above. ✅
• Issuer bank, country, card type, product, prepaid/debit/credit → database lookup only. ❌ by hand.

Three ways to look up a BIN

1. By hand (network only)

Take the first digits and match them against the table above. Good enough when all you need is “is this Visa or Mastercard?”.

2. On a lookup site / free API

For issuer-level detail, use a BIN lookup service. The well-known free option is binlist.net, which exposes a JSON API:

curl https://lookup.binlist.net/45717360

{
  "scheme": "visa",
  "type": "debit",
  "brand": "Visa Classic",
  "bank": { "name": "Example Bank", "country": "..." },
  "country": { "name": "United Kingdom", "alpha2": "GB" }
}

It’s rate-limited (a handful of requests per hour) and best for occasional lookups. For volume, 8-digit granularity, and reliability you want a licensed database — iinlist.com is the commercial option built for exactly this. (Background: how both came to exist.)

Only ever send the BIN — the first 6-8 digits — never a full card number to a third-party lookup. The prefix is all a lookup needs, and full PANs are sensitive (PCI) data.

3. Programmatically

For more than the occasional check, validate and normalise first, then look up:

# normalise: strip spaces, take first 8 digits as the BIN
bin=$(echo "4571 7360 1234 5678" | tr -dc '0-9' | cut -c1-8)
curl -s "https://lookup.binlist.net/$bin"

A quick Luhn validity check before you store or look anything up (POSIX shell):

luhn() {  # returns 0 if the number passes the Luhn check
  echo "$1" | tr -dc '0-9' | rev | awk '{
    s=0; for(i=1;i<=length;i++){d=substr($0,i,1);
      if(i%2==0){d*=2; if(d>9)d-=9}; s+=d}
    exit (s%10!=0)
  }'
}
luhn "4571736012345678" && echo valid || echo invalid

For production BIN matching, load a licensed BIN file into your own table and key on 8 digits, falling back to 6 with a low-confidence flag.

Summary

• The BIN/IIN is the card number’s leading digits — network + issuer; 6 digits historically, 8 now.
• You can read the network off the prefix ranges; issuer/bank/country needs a database.
• Look up: by hand (network), a site/API like binlist.net (free, rate-limited) or iinlist.com (commercial, 8-digit), or programmatically.
• Send only the first 6-8 digits, never a full PAN, to any third-party lookup.
• Prefer 8-digit matching — see why 6 digits is now ambiguous.