BIN 556103 — Lookup & Card Details

BIN 556103 is issued by National Westminster Bank Plc, from United Kingdom of Great Britain and Northern Ireland (the), on the Mastercard network, as a credit card.

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. For BIN 556103, that institution is National Westminster Bank Plc in United Kingdom of Great Britain and Northern Ireland (the). The card runs on the Mastercard network. Transactions settle in GBP.

Mastercard is a global network whose BINs fall in the 51–55 and 2221–2720 ranges, accepted at merchants worldwide.

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 556103 is institutional data under the ISO/IEC 7812 standard — looking it up reveals the issuing program, nothing about any cardholder.