London's favourite taxi app Hailo are now an official Avios collection partner. Collect 1 Avios per £1 spent on Hailo journeys, excluding airport transfers, by syncing your British Airways Executive Club number to the Hailo app. To celebrate the launch of the partnership, Hailo are offering all new users 400 Avios for their first UK transfer to London airports when you ride before the 31 December 2015. More details on their web site. I'd download the app now and add your BA account if I were you.