Which card begins with the number '6'?

The correct answer identifies the Discover Card, which is known to start with the number '6'. In the context of the payment card numbering system, specific prefixes are designated for different types of cards.

Discover is one of the major credit card networks and, unlike others, has a unique numéro de série that begins with '6'. Visa cards typically begin with '4', while MasterCard cards start with numbers between '51' and '55' and also include some newer ranges that start with '2'. American Express cards are distinct as well, starting with '34' or '37'. This is an important point for understanding how card issuer identification works and can assist in processing transactions accurately and efficiently within the payment system.

Knowing these details is crucial in navigating electronic transactions and helps professionals ensure compliance and accuracy in payment processing.