Travel site or airline: Where do you get the cheapest flights online?

There are countless ways to book a flight online, but usually only one is cheapest. — dpa

You know your destination, but when you type it into a search engine for a flight you get hundreds of results. Which one to choose? Essentially there are two kinds of websites. There's the flight referral sites and the flight brokers. Both will search the cheapest flights on offer.

After a destination is chosen, flight referral portals like Skyscanner, Kayak and Swoodoo will lead the customer directly to an airline. Occasionally you can choose between several flight offers and pick out the most favourably-priced one. It is only on the page of the air carrier that the user is required to provide personal data such as address, date of birth, and bank account details.

The flight brokers like Opodo or Expedia, by contrast, directly carry out a booking when one has selected a flight from the range of offers. This means that the user is authorising the platform to make the booking and so must provide his or her data to the website. In finalising the booking, the flight broker gets a fee that comes in addition to the regular air ticket price.

Julia Rehberg, of a consumer advocacy group in Hamburg, says that those who really want to save money should go directly to an airline's site. She says there are some portals that at first glance appear to offer flights cheaper. But often there are services that are not included that the traveller must then order and pay for afterwards.

Airline flight referral sites are best suited for providing initial orientation, answering one chief question: which airlines fly a certain route? According to the tech magazine c't, the problem is that users are often shown low-priced fares that don't include luggage.

However, those who book a budget-priced ticket and still want to take along a large suitcase can do an online booking for that separately. This can often be cheaper than booking a more expensive ticket that does include luggage.

In any case, travellers should not become too ecstatic when they see low-priced fares on alternative sites, says Aage Duenhaupt of the German air tourism company Tuifly. Besides the additional costs, it can happen that at the end of the online booking process the desired price is no longer available. One thing that has changed for the better is that high fees for payment by credit card, and pre-arranged insurance are no longer allowed.

Those who book online should be clear about one thing – that all the additionally desired services such as seat selection, the number of pieces of luggage or the choice of meal on board must also be booked online. "It can become expensive if you first do all this at the airport," says Duenhaupt.

Among the pitfalls to watch out for, the rules regarding oversize luggage are not always readily clear. The user should first carefully study what the rules are and when in doubt, ask questions before booking.

A further disadvantage of flight booking in the Internet is the lack of revocation rights. "You should always carefully look at everything one final time before pressing the 'buy' button," Rehberg says. After the booking it's a good idea to make a quick screenshot of the confirmation, as you won't always immediately receive an email.

If something really goes wrong, the user is best advised to contact the website and the airline, Rehberg says, "preferably in writing and by registered mail". – dpa