Related Clues:

• Place for a stamp
• Foreign-travel necessity
• Charging giant, informally
• Charge option
• 'Don't leave home without it' card
• Stamp collector?
• Visa competitor, familiarly
• Discover competition
• Credit card offerer
• Type of endorsement
• Shopper's card, often
• Certain charge card, informally
• International terminal document
• Alternative to Visa or MC
• American Express alternative