Video report by ITV News Consumer Editor Chris Choi
CompareTheMarket has been fined £17.9 million by the competition watchdog for being found to keep the cost of home insurance premiums artificially high.
The price comparison site ensured it was not undercut by preventing home insurers on its platform from offering lower prices on similar websites, the competition regulator said.
As a result, customers were more likely to pay higher premiums, the Competition and Markets Authority (CMA) said.
CompareTheMarket said it “fundamentally disagrees” with the CMA’s decision.
The fine comes more than two years after the watchdog first said it thought the price comparison site, which is part of BGL Group, could be breaking the law.
The regulator said its investigations found these “most favoured nation” clauses in contracts - which prohibit insurers from offering cheaper insurance to customers elsewhere - were used between December 2015 and December 2017.
Michael Grenfell, the CMA’s executive director for enforcement, said: “Price comparison websites are excellent for consumers. They promote competition between providers, offer choice for customers, and make it easier for consumers to find the best bargains.
“It is therefore unacceptable that CompareTheMarket, which has been the largest price comparison site for home insurance for several years, used clauses in its contracts that restricted home insurers from offering bigger discounts on competing websites – so limiting the bargains potentially available to consumers."
A spokeswoman for the company said: “CompareTheMarket.com is disappointed with the CMA’s decision and does not recognise its analysis of the home insurance market.
“We fundamentally disagree with the conclusions the CMA has drawn and will be carefully examining the detailed rationale behind the decision and considering all of our options.
“For 14 years CompareTheMarket.com and the other price comparison websites have revolutionised the way in which consumers shop for their insurance. In the past year alone, we have helped more than six million customers save money."