Apple is facing a £3 billion ($4 billion) class-action lawsuit from a consumer advocacy group that accused the company of overcharging millions of British customers for iCloud storage services.
If the case is successful, the payout could equate to about £70 per affected customer, with the class action covering 40 million people who have used and paid for Apple's iCloud storage since October 2015.
The consumer group, Which?, alleges that Apple has locked users into paying "rip-off prices" for digital storage by embedding iCloud as the default and often only practical option for backing up data on iPhones and other Apple devices.
Which? said Apple's high fees for expanded storage leave users with few alternatives which creates a "pay up or lose out" scenario for consumers who need more than the limited free storage offered by the company.
Which? has enlisted an international law firm to handle the suit, marking one of the most high-profile legal challenges the company has faced in the UK.
Apple, however, has denied the allegations and plans to "vigorously defend" itself in court.
The lawsuit follows a similar case filed against Apple in the U.S. in March, where American plaintiffs have raised concerns about iCloud pricing practices.
That case has yet to conclude, but its existence has amplified scrutiny of Apple's pricing model on both sides of the Atlantic.
The case highlights concerns in Europe and the U.S. about the potential for tech companies to abuse their market positions.
As Apple battles the new legal challenge, the outcome could have significant implications not only for British customers but for broader regulatory scrutiny and tech company policies in Europe.