BIN 666581 — Lookup & Card Details

BIN 666581 is on the Maestro / debit network network.

A Bank Identification Number (BIN, or Issuer Identification Number / IIN) is the first 6 to 8 digits of any payment card. It tells the payment network which institution issued the card, what kind of card it is, and where it was issued. The card runs on the Maestro / debit network network.

This BIN falls in the 50/56–69 space used by Maestro and regional debit, store and private-label card programs — ranges that sit outside the major global credit networks but are routed through their own debit rails.

In practice this prefix is what a checkout sees first — risk engines score it, gateways route on it, and merchants use it to decide whether to accept the card class at all. BIN 666581 is institutional data under the ISO/IEC 7812 standard — looking it up reveals the issuing program, nothing about any cardholder.