How the first digits identify an issuer
Card numbers follow ISO/IEC 7812-1. The first digit is the major industry identifier: 4 and 5 for banking, 3 for travel and entertainment. The leading block is the issuer identification number, which the industry still calls the BIN after its older name, bank identification number. Then come the digits that identify the individual account, and a final check digit.
For decades the issuer block was six digits long. The standard was revised to extend it to eight because the networks were running short of six digit ranges, and both lengths are now in circulation. This tool sends exactly what you enter, whether six, seven or eight digits. If eight digits return nothing from the database, retry with the first six.
Reading the result
Network is the card scheme, such as Visa, Mastercard or American Express. It is worked out on the server from the same prefix ranges a checkout form uses, and falls back to the database's value for a range those rules do not cover. Type is debit or credit, with Prepaid printed beneath when the database flags the range that way. Issuing bank is the institution that owns the BIN.
The details table adds Brand / level, the product name the database holds for the range when it has one, and Valid lengths, the digit counts that network issues. A dash means the database had no value for that field, which is common for the bank name on small or recently assigned ranges. Prepaid shows Yes, No or a dash for unknown.
When bank details are missing
A note under the table means the result came from number-range rules alone, for one of four reasons: the BIN is not in the public issuer database, the database's free quota is used up, it returned an error status, or it did not respond within six seconds. In each case bank, type and country show a dash instead of a guess.
This site also limits lookups to ten a minute per address, and answers are cached for a day or more, so an immediate retry can return the same note. If a BIN you know to be real keeps coming back as not in the database, the range is probably too new or too small to have been catalogued.
How merchants and support teams use BIN data
The commonest use is fraud screening. An order where the card was issued in one country, the delivery address is in a second and the buyer's connection is in a third deserves a manual look. IP lookup covers the connection side. Prepaid cards are legitimate, but they are also a frequent choice for free-trial abuse and one-off fraudulent orders.
Support teams use the same data to explain declines: a card issued abroad may be blocked for foreign transactions, and a prepaid card may not accept the recurring charges a subscription needs. Processors use it for routing and for fees that differ between debit and credit. In each case the BIN narrows the question, and the issuer's authorisation response answers it.
Limits, accuracy and what never to enter
Public BIN tables are assembled from open sources, not published by the card networks, and they age. Banks merge, sell card portfolios and lend ranges to fintech programmes run under a sponsor bank, so the name returned can be out of date or unfamiliar to the cardholder. The networks' own tables, supplied to acquirers and processors, are the authoritative source.
Only the BIN is needed, so only the BIN should be typed. The box stops at ten characters, a ninth digit triggers a warning, and the server rejects longer input outright. The digits you submit go to this site, are passed to the issuer database, and appear in the page address so a result can be bookmarked. To test whether a complete number is well formed, use the credit card validator, which sends nothing anywhere.