Carrot Insurance uses phone data to measure journey length, acceleration and braking - but some say it often fails to work or wrongly records data. In one instance, a passenger was on a train and the app recorded the user as "speeding".
The person on the train was marked as speeding, which Carrot said "can occur in some very rare instances when customers pair their phone to an additional Bluetooth device". One woman, 28-year-old Jess, said Carrot cancelled her policy in December 2018 because she was not using the app - which she said was not working properly. "In the end I lost two years no claims discount," she told the BBC.