Related Clues:

• American Express alternative
• Something that's stamped
• Midsize Kia
• Border-crossing paper
• Dow 30 company
• Passport stamp or credit card
• Passport stamp or well-known credit card
• Stamp affixed to passport as permission to enter country
• It allows the bearer to enter the country issuing it
• Authorisation to enter a country
• One pass as four get up
• You may need this to get permission to travel round by way of the South
• Pass the half-dozen as it comes back
• The way four is back for permission to come in
• Half a dozen, as it's up for travel (4)