TikTok will pay a £12.7m fine to the UK’s data watchdog after dropping an appeal against a ruling that it did not do enough to keep children below the age of 13 off the platform.

The video app was punished by the Information Commissioner’s Office in 2023 for inadequate checks of who was using the platform, and failing to remove underage users.

When issuing the fine the ICO said TikTok had done “very little, if anything” to address underage use of its service.

TikTok has a minimum user age of 13 but failure to enforce that limit resulted in up to 1.75 million UK children under 13 using the service in 2020, the ICO said. TikTok also failed to provide users with information about how their data was being collected and used, and neglected to obtain parental consent.

Emily Keaney, the ICO’s deputy commissioner, said: “Our successful action against TikTok shows how important it is for companies to have the right protections in place, including to prevent access by children who are not old enough to be using their services.”

Chinese-owned TikTok said it disagreed with the ruling but had decided to pay the fine because it related to a period between 2018 and 2020, after which it had implemented “many youth safety measures and policies”.

TikTok, which has more than 30m users in the UK, has also withdrawn an appeal against an ICO request for information about how its algorithm processes teenagers’ personal data – and how it serves potentially harmful content. The ICO said it would now resume the investigation.

At the time the fine was issued, the then information commissioner, John Edwards, told the Guardian that TikTok was “not doing enough” on multiple fronts.

“Our findings were that TikTok were not doing enough to prevent under-13s accessing their platform, they were not doing enough when they became aware of under-13s to get rid of them, and they were not doing enough to detect under-13s on there,” he said.

Age-checking measures at tech platforms will be at the vanguard of the government’s new under-16 age limit for accessing social media platforms, which comes into force next year.

The UK’s communications watchdog, Ofcom, has said “more action from the tech industry is needed” on enforcing age limits as the ban approaches. In Australia, which introduced a social media ban for under-16s last December, the eSafety commissioner has said a “substantial proportion” of under-16s in the country have kept their accounts, managed to create new ones or bypassed age-gating systems.