Epic Games, the studio behind the hit game Fortnite, has started legal action against Apple and Google in the UK.

Both Apple and Google removed Fortnite from their smartphone app stores in a row over the cut of sales they take from developers.

Epic Games claims the two tech giants' rules are in violation of UK competition laws.

Fortnite-maker Epic Games sues Apple and Google in UK https://t.co/WrwowFsXwf

— BBC News Technology (@BBCTech) January 15, 2021

But both companies say Epic Games broke their terms and conditions by trying to bypass their payment systems.

Apple said Epic Games' action had been "reckless".

When people buy an app, subscription or in-app item on Apple's App Store or the Google Play store, the tech giants take a cut of the fee.

Typically they take a 30% cut, although in some cases the rate is lower.

For this reason, some companies charge more for subscriptions when people buy directly in the app instead of on their website, while others do not sell subscriptions in-app at all. Companies are also banned from telling app users a cheaper deal is available.

Epic Games has previously said it thinks a 30% cut is too much, given the amount of money and effort it invests in developing its games.

In August 2019, the company bypassed the Apple and Google payment systems to let Fortnite players buy virtual currency at a lower price, direct from Epic.

Both app stores then removed Fortnite from their services, and Apple terminated Epic Games' developer account.

In documents submitted to the UK's Competition Appeal Tribunal (CTA), Epic Games alleges that Apple and Google have abused their dominance over their smartphone operating systems.

While Apple produces iOS exclusively for its iPhones, Google's Android software is open-source so in theory any smartphone-maker can use it.

However, Google also produces a suite of proprietary tools including Maps, Search and the Play Store, which power some of the most popular services on smartphones. Phone-makers must enter an agreement with Google to use them on their devices.

In a statement, Epic Games said: "We believe that this is an important argument to make on behalf of consumers and developers in the UK and around the world who are impacted by Apple and Google's misuse of market power."

It has taken similar legal action in the US and Australia.

On Thursday, 21 January, the CTA will decide whether Epic Games can include US-based divisions of Apple and Google in its legal action.