Warning – the booking sites that may rank hotels higher if they get commission

When you search for a hotel via a hotel broker or comparison site, the default results usually show 'recommended' or 'top pick' hotels, chosen according to the site's algorithms. Price, location, reviews and other factors relevant to customers usually feed in to this.

But a MoneySavingExpert.com investigation has found that about half of the big hotel-booking sites also factor in the commission they receive for bookings when ranking accommodation – in other words, a hotel may be ranked higher than similar alternatives if a booking site is paid, or paid more, when a customer makes a reservation.

Eight sites including Booking.com, Expedia and Kayak say that commission may affect rankings – and all clearly state this to customers on their sites. By contrast, other sites such as Lastminute.com and Skyscanner told us any commercial agreements have no impact on rankings.

It comes after the competition watchdog, which has been working to make hotel booking websites more transparent, stressed earlier this year that sites should be clear to customers if rankings may be affected by commission. It warned that default search rankings are "crucial" for many when choosing a hotel.

When using a hotel broker or comparison site, always remember that a range of factors affect the default results and you can instead use different filters to search by the factors which are most important to you, eg, price or reviews. If you've time, check multiple sites to ensure you get the best price too.

For more ways to cut the cost of holiday accommodation, see our Cheap Hotels guide.

How do different sites' default results rank hotels?

We looked at the default search rankings of some of the hotel booking sites most commonly used by UK customers – we selected these from among those the Competition and Markets Authority has looked at and those we've previously featured on MoneySavingExpert. We checked 14 sites in total and found eight consider commercial factors when returning results:

How do commercial factors affect hotel rankings?

The algorithms used to rank hotels in searches are complicated and differ from site to site. As multiple factors are typically involved and it's not always clear which hotels sites are paid to feature, it's impossible to give specific examples of when individual hotels have been ranked differently. But it's possible a hotel may be ranked higher than similar alternatives due to the fact it earns the booking site more money.

The issue featured prominently in the Competition and Markets Authority's recent investigation into hotel booking sites. Its guidance document earlier this year identified "failure to disclose the effect of payments on search results" as a key concern, and said it was vital consumers were given a clear explanation of any impact commercial factors may have on search results – something all sites did when we checked.

It added: "Where hotel booking websites fail to clearly and effectively explain to consumers the methodology for determining the ranking, consumers may take a transactional decision without sufficient knowledge of the commercial relationship underlying the recommendations.

"For example, consumers may interpret the search results presented in the default listing as being tailored entirely based on their search criteria and in their interest, without any direct reference to the interests of the hotel booking website." 

'Keep your wits about you to find the best deal'

Guy Anker, deputy editor at MoneySavingExpert.com, said: "Ranking hotels based on commission could be harmful to users, but you could argue that sites are at least being transparent about their practices. Yet don't see the fact that a hotel booking site could skew its rankings as a reason not to use one. After all, they may still offer the best price.

“But you'll need to keep your wits about you to find the best deal, so don't automatically go for the hotel at the top of the search. Before choosing, read reviews, compare prices between sites and the hotel direct, and also check location, booking flexibility, room type and what extras are provided, such as breakfast."

For more help on how to find the best hotel deals, see our Cheap Hotels guide.