The Competition Markets Authority is investigating whether booking websites actually allow customers to find the best deals.It is focusing on four key areas: search results, pressure selling, discount claims, and hidden charges.The investigation was prompted by concerns some websites could be breaking customer law.

LONDON – The UK Competition Markets Authority (CMA) on Friday opened an investigation into whether accommodation booking websites really give customers the best hotel deals available.

The investigation was prompted by concerns about clarity, accuracy, and presentation of information on sites, which the CMA said could mislead people and potentially break consumer law.

“Around 70% of people who shopped around for hotels last year used these sites and they should all be confident they have chosen the best accommodation for their needs and are getting a good deal,” Andrea Coscelli, chief executive of the CMA, said in a statement.

She said the CMA was concerned websites were "making it difficult for people to make the right choice."

No specific companies or services are named but the best-known examples in the UK include Trivago, Hotels Tonight, and

The CMA's investigation will focus on four key areas:

how hotels are ranked in search results and to what extent results are influenced the commission a hotel pays the site; pressure selling, and whether claims about how many people are looking at the same room or how long a price is available, create a false impression of availability; discount claims, and whether these offer a fair comparison for customers; and the extent of hidden charges, such as unexpected taxes and booking fees.

On Friday, the CMA wrote to companies across the sector asking for more information about the way they operate and is calling on customers to share any relevant experiences.

The CMA said websites must be clear on how they make money, provide accurate information to customers, use people's personal data responsibly, and be easy to use in order to comply with consumer protection laws.