17 of the UKs top 50 travel brands lack a mobile presence – meaning they have neither an app or mobile site. Thats according to the IAB UKs Mobile Travel Audit, which looked at the top travel companies by ad spend.

Of the 50, 24 have a mobile-optimised site, plus one responsively designed site, for comparison site Trivago. Just two of the brands have a site specifically designed for tablet devices. 

Half have a smartphone app, with the full 25 available on iOS, and 22 on Android. 16 of the brands have both a mobile site and app – to see the full list, check out the Venn diagram above.

56 per cent of these apps included transactional functionality and, of the 17 transport brands included, just three offered mobile ticketing: EasyJet, British Airways and Lufthansa.

“With British consumers now spending more time than ever online, an average of 43 hours per month, it’s surprising to see that such a large percentage of the top 50 UK travel advertisers still have no mobile presence,” said IAB head of mobile Alex Kozloff. “Mobile now accounts for 14 per cent of total digital spend, it’s a medium that can’t be ignored.”

The study also revealed that, during the sample period of September-October 2013, just 21 of these brands optimised their search campaigns for mobile. And four of the brands investing in mobile search actually sent users to non-optimised sites.