The regulator did not name the 11 companies, but said that where platforms do not comply with the law, they will face enforcement action.

The move follows an ongoing review of social media and video sharing platforms as part of the ICO’s Children’s Code Strategy. The ICO’s Tech Lab reviewed 34 firms, with a focus on the process young people go through to sign up for online accounts. 

Some platforms were “not doing enough” to protect children’s privacy, the watchdog said. 

The ICO has asked the 11 platforms about issues relating to default privacy settings, geolocation or age assurance, and to explain how their approach conforms with the code, following concerns raised by the review.

It is also speaking to some of the companies about targeted advertising to ensure practices are in line with the law and the code.

Further evidence is needed to improve understanding of how social media platforms and video sharing platforms are impacting children’s privacy, the ICO said.

The regulator has launched a call for interested stakeholders to share their views and evidence on two areas of children’s privacy: how children’s personal information is used in ‘recommender’ systems; and recent developments in the use of age assurance to identify children under 13 years old. The consultation is open until 11th October.

Emily Keaney, deputy commissioner said: “There is no excuse for online services likely to be accessed by children to have poor privacy practices. Where organisations fail to protect children’s personal information, we will step in and take action.

“Online services and platforms have a duty of care to children. Poorly designed products and services can leave children at risk of serious harm from abuse, bullying and even loss of control of their personal information.”