Airline extra charges have risen two-thirds However, some airlines have substituted card fees with a 'booking' fee of between £6 and £9. Bob Atkinson, from Travelsupermarket, said: "The research has shown that the cost and rules of both compulsory and optional airline fees and extras have gone up year on year - some quite considerably. So before you book, it's vital to check what additional fees you'll incur and also make sure you know the airline's rules for things like baggage allowances. Don't assume all airlines are the same as they aren't and the fees vary widely. He added: "In recent years there has been a blurring of how low-cost, holiday airlines and traditional full-service airlines operate.