Apple has rejected South Korea's decision to fine it 20.81 billion won ($15.6 million) over its App Store payment practices, maintaining that its policies comply with Korean law and saying it is reviewing its options.

Google also objected to Wednesday's ruling, which imposed a combined 63.71 billion won in penalties on the two US tech giants for effectively forcing developers to use their own payment systems and unfairly delaying app reviews.

"We respectfully disagree with today's decision and believe the changes we have implemented to date comply with the Telecommunications Business Act," an Apple spokesperson told The Korea Herald. "We are evaluating our options in accordance with Korean law."

Apple defended its contribution to Korea's app economy, saying the App Store ecosystem facilitated 38.1 trillion won in developer billings and sales last year, with more than 90 percent of that commerce going to developers without commissions paid to Apple.

"The App Store has been an engine of innovation and economic growth in Korea, making it possible for developers big and small to reach users on a platform they can trust," the spokesperson said.

Google, which received a larger fine of 42.9 billion won, said the regulator had failed to adequately recognize its efforts to comply with Korean law and expand developers' payment options.

The company cited recently announced changes to increase payment flexibility and reduce service fees. It will decide how to respond after reviewing the written ruling, according to local media.

The Korea Media and Communications Commission, however, said Google's planned changes had yet to take effect in Korea and could not be reflected in the penalties.

The regulator found that both companies charged developers a 26 percent commission for using third-party payment systems while imposing restrictions that made those alternatives commercially unattractive.

Apple also faced penalties for charging Korean developers higher effective commissions than their overseas counterparts between 2015 and 2023, a practice the regulator estimated generated 149.6 billion won in additional fees.

Wednesday's decision was the first enforcement action under Korea's 2021 law banning mandatory in-app payment systems.

Both companies must submit compliance plans within one month of receiving the corrective orders and implement changes within three months, including allowing external payment links and improving app review procedures.

Neither company has confirmed plans to challenge the ruling in court.

By Moon Joon-hyun (mjh@heraldcorp.com)

By Jie Ye-eun (yeeun@heraldcorp.com)