The term GREEN CARD ISSUER can be solved by two crossword solutions: AMEX (4 letters) and AMERICANEXPRESS (15 letters). American Express, commonly known as AMEX, is a multinational financial services corporation that is best known for its credit card, charge card, and traveler's cheque businesses. It is one of the 30 components of the Dow Jones Industrial Average. Founded in 1850, it is one of the oldest financial services companies in the world. American Express offers a variety of credit cards, including the Green Card, which is designed to help customers build their credit history.