Prefix ranges used
| Network | Leading digits |
|---|---|
| Visa | 4 |
| Mastercard | 2221–2720, 51–55 |
| American Express | 34, 37 |
| Discover | 6011, 644–649, 65 |
| JCB | 3528–3589 |
| Diners Club | 300–305, 36, 38 |
| UnionPay | 62 |
What the first digits tell you
The leading digits of a card number are the issuer identification number (IIN), also called the BIN. The first one to four digits identify the card network, which decides the dispute rules and reason codes that apply. The full six to eight digits identify the issuer, but that needs a licensed BIN database, so this tool doesn't claim it.
Limits
- Ranges are reassigned over time, and some cards run on more than one network (some UnionPay 62 cards are also accepted on Discover's network). Treat the answer as a quick check, not proof.
- For a disputed order, use the network and card details your processor recorded on the charge; Verdikx keeps those with the order's evidence record.
- Blocklists in Verdikx store a card's BIN and last four only, never the full number.
Frequently asked questions
What is a BIN or IIN?
The first six to eight digits of a card number identify the issuer: the issuer identification number (IIN), often called the bank identification number (BIN). The first one to four digits are enough to tell the card network.
Does this tool show the issuing bank or country?
No. It uses a static table of the networks' published prefix ranges, so it names the network only. Issuer, country and card type need a licensed BIN database; your processor usually shows them on each charge.
Is it safe to type card digits here?
The lookup runs in your browser and sends nothing anywhere. It keeps at most the first eight digits. Never enter or share a full card number.
Sources
- Wikipedia: Payment card number (issuer identification number ranges) (checked October 5, 2026)
Last reviewed by Verdikx Research.