The UK's Age Appropriate Design Code — published by the Information Commissioner's Office and in force since September 2021 — applies to any online service likely to be accessed by children in the UK. Built on GDPR principles, the Code sets 15 standards including privacy-by-default settings, data minimization, restrictions on profiling and "nudge" techniques against children, and clear age-appropriate transparency.
The Code has influenced equivalent regimes in California (the California Age-Appropriate Design Code Act), Australia, and the EU, and is the most-cited blueprint for child-safety-by-design in online services globally.