Airlines use code letters to reference different types or tiers of passenger tickets. The exact definition varies between airlines, but a Class C ticket typically refers to a business class ticket for an international flight. It has no restrictions such as length of stay or fee for changing the dates.
Business Class Designation
Airlines designate tickets as first class, business class or economy class. First class provides the most luxurious travel experience, but business class can come a close second. Class C tickets refer to a business class ticket for an international flight that's considered full fare, which means the ticket is eligible for an upgrade to first class and carries less risk of travel fees than the lower class tickets. The specific benefits of Class C tickets vary between airlines. Benefits can include early boarding, no restrictions on trip length, no fees on changing the ticket's dates after purchase and additional airline miles for reward programs.