How card numbers work: what each digit on your card means
By SendPay Business · · 2 min read
The long number on a payment card is not random. Its digits say which network the card runs on, which company issued it and which account it belongs to, and the last digit helps catch typing mistakes.
The first digits
The first digit points to the network: 4 for Visa, 5 and some ranges starting with 2 for Mastercard, and 34 or 37 for American Express. The first six to eight digits together are the BIN, which identifies the company that issued the card.
The middle digits
After the BIN come the digits that identify the individual card account. Most cards have 16 digits in total, but the standard allows card numbers from 8 to 19 digits, and American Express cards have 15.
The check digit
The last digit is worked out from the others using a simple formula called the Luhn check. If someone mistypes one digit, the check usually fails, so a checkout can flag the error before trying the payment. Passing the check does not mean a card is real or has money on it.
Where SendPay fits
SendPay platforms can issue branded Visa cards to your customers, from £0.20 per virtual card and £4 per physical card before shipping, powered by licensed partners. SendPay tells you in writing which licences apply to your platform before you pay.
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This guide is general information, not legal or financial advice. SendPay Business is a technology company, not a bank, and does not take deposits; regulated services on the platforms are provided by licensed partners. PayPal, Patreon and Substack are named as reference points only and are not affiliated with SendPay Business.