Ofcom has launched an investigation into whether TikTok is failing to protect children from harmful content.
The regulator will examine whether the video-sharing app is complying with elements of the Online Safety Act, which has been rolled out in stages since being passed into law in October 2023.
It comes after an Ofcom review said TikTok was "failing" to take steps to protect children "despite overwhelming evidence of harm", and the publication of another report that "highlighted concerns about children being exposed to harmful content on TikTok".
In addition, Ofcom has said some systems used by TikTok to check users' ages "may have failed to correctly identify a significant proportion of children".
Ofcom said: "In light of these concerns, this investigation will seek to establish whether there are reasonable grounds to believe that TikTok has failed, or is failing, to comply with its legal obligations."
"The opening of an investigation does not mean that Ofcom has reached any conclusion about whether the provider has breached its duties," it added.
If failures are identified, Ofcom can impose fines of up to £18m or 10% of qualifying worldwide revenue, whichever is greater.
It can also seek a court order to force third parties - such as internet providers - to take action, which could include blocking access.
A TikTok spokesperson said: "We strictly enforce age-appropriate experiences through expert-informed platform rules and advanced age inference technologies, in line with major industry peers.
"In the eight years since TikTok launched in the UK, we have invested billions in platform safety.
"We are confident that we meet our Online Safety Act obligations and will work with Ofcom to demonstrate this."
The probe comes a month after the government announced a ban on social media for under-16s.
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The ban, expected to come into force in spring 2027, will cover platforms including Snapchat, TikTok, YouTube, Instagram, Facebook and X.
It was also announced on Wednesday that 16 and 17-year-olds will be able to opt in to overnight social media curfews and disable infinite scrolling.
(c) Sky News 2026: TikTok being investigated by Ofcom over child safety measures
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