Apple has abused its dominant position by charging app developers an unfair 30% commission through its App Store, costing British consumers up to 1.5 billion pounds ($1.8 billion), a London tribunal heard on Monday.

Apple is heading to court in London on Monday to defend against a class-action lawsuit seeking £1.5 billion ($1.9 billion) in damages

Apple is accused of overcharging consumers for software sold via the App Store in a £1.5 billion class-action lawsuit bought by Rachael Kent-Aitken on behalf of 20 million UK consumers. (That equates to about $1.8 billion in US dollars.)

Tech giant Apple is expected to face overcharging claims in Britain on Monday based on a complaint led by a King's College London academic who said the company is breaking competition laws.

Apple was accused Monday of abusing the dominant position of its app store at the start of a court trial in the UK, with plaintiffs seeking £1.5 billion ($1.8 billion)

Apple is facing a massive legal battle in the UK over its App Store fees. Here's everything you need to know about the lawsuit.