# The Online Safety Act 2023 (Category 1, Category 2A and Category 2B Threshold Conditions) Regulations 2025, Regulation 3: Category 1 threshold conditions


(1) The Category 1 threshold conditions are met by a regulated user-to-user service where, in respect of the user-to-user part of that service, it—
(a) (i) has an average number of monthly active United Kingdom users that exceeds 34 million, and
(ii) uses a content recommender system, or
(b) (i) has an average number of monthly active United Kingdom users that exceeds 7 million,
(ii) uses a content recommender system, and
(iii) provides a functionality for users to forward or share regulated user-generated content on the service with other users of that service.
(2) In paragraph (1), a “content recommender system” means a system, used by the provider of a regulated user-to-user service in respect of the user-to-user part of that service, that uses algorithms which by means of machine learning or other techniques determines, or otherwise affects, the way in which regulated user-generated content of a user, whether alone or with other content, may be encountered by other users of the service.

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Source: https://www.legislation.gov.uk/uksi/2025/226/regulation/3 (the official version)
Page: https://openlegislation.uk/online-safety-act-2023-category-1-category-2a-and-category-2b-threshold-conditions-regulations-2025/regulation-3
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.