UK platforms now owe children a legal duty of care

The short answer

The Online Safety Act gives large platforms a legal duty to assess and reduce the risk that children encounter serious harms online, enforced by a regulator rather than left to a platform's own judgement. The duties arrived in stages, so what a platform must actually do in 2026 rests on rules that were still being phased in through 2025.

What the evidence says

The Online Safety Act 2023 received Royal Assent on 26 October 2023, and the Act's text sets out duties on providers of user-to-user services and search services, including specific safety duties protecting children and a duty to carry out a children's risk assessment where a service is likely to be accessed by children. According to the government's explainer of the Act, Ofcom's protection of children codes of practice were laid in Parliament on 24 April 2025 together with risk-assessment guidance, and services likely to be accessed by children then had three months, to a deadline of 24 July 2025, to complete their children's risk assessments. The same explainer records that, from January 2025, platforms hosting pornographic content had to apply the age checks required by Ofcom's guidance. The Act creates tiered obligations, with larger "Category 1" services facing more extensive duties, and gives Ofcom powers to require transparency reports and fine non-compliant providers.

For context

A duty to assess and mitigate risk is not the same as a guarantee that children will never encounter harmful content; the Act requires proportionate systems and processes, and what counts as proportionate for a given service sits in codes of practice rather than in the Act's own text. Age assurance in this framework covers methods from self-declaration to technical estimation or verification, and which is expected depends on the risk a type of content poses. Because duties commenced in phases through 2025, a claim that a platform "complies with the Online Safety Act" needs a date attached to mean very much.

A practical next step

You could check whether a platform your child uses publishes a children's risk assessment or safety summary, since the Act's transparency provisions are intended to make that kind of document findable, and treat its absence as a question worth raising with the service rather than proof of non-compliance.

• Which category of service does this platform fall into, and does that change what it must do?
• Has the platform changed its age-checking approach since mid-2025, when the children's duties took effect?
• Does a safety claim describe a completed risk assessment, or only an intention to carry one out?

The Act shifts responsibility for children's online safety toward platforms and a regulator with enforcement powers, but it does so through phased, code-based duties rather than one fixed rulebook, so its practical effect is still visible mainly through the codes Ofcom has published and continues to update.