Can I use my Mileage Plan™ miles to book a cruise? January 03, 2019 15:35 Updated Unfortunately, Mileage Plan™ miles cannot be used to purchase your cruise. Related articles What is Onboard Credit (OBC)? Can my Mileage Plan™ miles be combined with cruise offers? How do I earn Mileage Plan™ miles on my cruise? How can I earn the most Mileage Plan™ miles? Can all guests on my cruise reservation earn Mileage Plan™ miles?