An annual study of how much airlines charge passengers for extras including checked baggage and credit card bookings has shown that in just two years they have risen by 66 per cent. The research is conducted by aviation consultant IdeaWorksCompany and Amadeus, a provider of travel technology.

In 2009, ancillary services accounted for revenues of £8.6 billion. This rose to £11.7 billion in 2010, and last year increased to £14.23 billion. IdeaWorksCompany president, Jay Sorensen, said that in the past it was budget carriers who were known for adding extras to the basic price of a ticket. Now it is an important stream of revenue for airlines around the world.

Sorensen explained that when the first report was published in 2007, €1.72 billion from ancillary earnings was being filed into the financial statements of just 23 airlines. Within four years this amount had risen to €18.23 billion with 50 airlines admitting to adding extras to the price of tickets.

Last year, budget carrier easyJet collected £695 million from charges including a booking admin fee of £9, a credit card processing charge of £7.50 and baggage charges for a return flight of up to £31.

Rival Ryanair collected £692 million through charges for extras including up to £40 for checking baggage, £12 for checking-in via the web and a £6 admin fee. A Global Business Travel Association spokesman said there needed to be more transparency across the industry so that passengers know exactly what they are paying for, and how much they will have to pay, when they begin searching for an airline ticket.