Apple’s operating system for iPads has been designated as a “gatekeeper” under the bloc’s landmark tech rules by EU antitrust regulators because of its importance to business users, the European Commission said on Monday.

Under the Digital Markets Act which came into force this year, 22 services owned by Apple, Google, Microsoft, Amazon, Meta Platforms and TikTok owner ByteDance have already been labelled gatekeepers which control access to their platforms.

The European executive’s decision followed an investigation launched in September last year. Apple’s operating system iOS, its browser Safari and its App Store were designated gatekeepers last year.

“Our market investigation showed that despite not meeting the thresholds, iPadOS constitutes an important gateway on which many companies rely to reach their customers,” EU antitrust chief Margrethe Vestager said in a statement.

The commission said Apple’s business user numbers exceeded the quantitative threshold by 11 times, while its end user numbers were close to the threshold and were predicted to rise in the near future.

It said both business users and end users are locked into iPadOS because of its large ecosystem. Apple, which has six months to comply with the DMA, said it will “continue to constructively engage with the European Commission to comply with the DMA across all designated services”.