Research by Consumer Intelligence suggests 31 per cent of people enter fake details into price comparison websites in order to avoid follow-up calls, but when these dont match those the insurers have on record, the average price goes up by around £126. Almost two in five people (39pc) say they deliberately use the wrong phone number, while 10pc admit to entering a fake address and 8pc a made-up name. But in 80pc of cases quotes were cheaper when the correct details were given, and on average the search produced 18 more quotes to choose from. Ian Hughes, chief executive of Consumer Intelligence, said: It is tempting to put in fake details to avoid follow-up calls and emails when using price comparison websites, but it really does pay to keep it real. The quotes produced for even slightly incorrect data will be more expensive generally and there will be fewer to choose from which will mean missing out on savings. With motor insurance premiums rising it is a false economy to put in false information and it is worth a few follow-up calls to maximise [your] savings. The company reports that the well-known insurers that refuse to provide quotes for fake data include Allianz, AXA, Co-Op, John Lewis, Legal & General, Marks & Spencer, Nationwide, Post Office, RIAS, Santander and Swiftcover.