U.K. motor finance companies are braced to pay out £8.2 billion in compensation for selling unfair car loans to 14 million customers between 2007 and 2024. This follows a U.K. Supreme Court ruling on Aug. 1 that the companies had broken laws and regulations by failing to disclose important information, which denied consumers the opportunity to shop around for better deals or negotiate.

Ruth Prickett graduated from Cambridge University with a BA hons in History and has specialized in business and finance journalism for the past 20 years. She was editor of Financial Management, the magazine...