Are MasterCards that start with a "2" valid?
Yes, MasterCard has begun to issue cards that begin with a 2. Over the years, millions of cards have been issued and the old 5 series of numbers as begun to run low. If one of your customers presents a MasterCard beginning with a 2, it is legitimate and you should process the sale using the same security procedures as you would with a card beginning with a 5. Below please find more information on the 2 series directly from MasterCard.