The Online Safety Act 2023 requires certain online services to have in place greater levels of transparency and accountability, empower users with more choice and control, and protect users from fraudulent advertising.
These services, known as categorised services, are some of the most widely used online services in the UK. Ofcom, as the online safety regulator, is responsible for ensuring that providers of these services comply with the additional responsibilities placed upon them.
The published register of categorised services sets out which services are categorised and are therefore subject to additional duties under the Act.
Register of categorised services
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:
- has an average number of monthly active United Kingdom users that exceeds 34 million, and uses a content recommender system; or
- has an average number of monthly active United Kingdom users that exceeds 7 million, uses a content recommender system, and provides a functionality for users to forward or share regulated user-generated content on the service with other users of that service.
| Service name | Service description | Service provider |
|---|---|---|
| Regulated user-to-user service of a combined service - Social media service | Meta Platforms, Inc | |
| Regulated user-to-user service of a combined service – Social media service | Meta Platforms, Inc. | |
| Regulated user-to-user service – Social media service | Pinterest Europe, Ltd | |
| Quora | Regulated user-to-user service – Discussion forum | Quora, Inc. |
| Regulated user-to-user service – Discussion forum | Reddit, Inc | |
| Roblox | Regulated user-to-user service – Gaming service | Roblox Corporation |
| Snapchat | Regulated user-to-user service – Social media service | Snap Group Limited |
| TikTok | Regulated user-to-user service – Social media service | TikTok Information Technologies UK Limited |
| Regulated user-to-user service – Messaging service | WhatsApp LLC | |
| X | Regulated user-to-user service – Social media service | X Internet Unlimited Company |
| YouTube | Regulated user-to-user service – Video-sharing service | Google LLC |
Category 2A threshold conditions are met by a regulated search service or a combined service where, the search engine:
- has an average number of monthly active United Kingdom users that exceeds 7 million, and
- is not a search engine which (i) only enables a user to search only selected websites or databases in relation to a specific topic, theme or genre of search content, and (ii) is facilitated by means of a relevant arrangement.
| Service name | Service description | Service provider |
|---|---|---|
| Google Search | Regulated search service – Search service | Google LLC |
| Bing | Regulated search service – Search service | Microsoft Ireland Operations Limited |
| ChatGPT (ChatGPT Search) | Search engine of a regulated search service – AI Search Assistant [1] | OpenAI OpCo, LLC |
| Facebook (Feed Deep Dive) | Search engine – AI Search Assistant [2] | Meta Platforms, Inc. |
[1] ChatGPT Search on ChatGPT (‘ChatGPT Search’) is a search engine included on ChatGPT, which is therefore a regulated search service. As such, OpenAI OpCo, LLC is required to meet the additional safety duties for Category 2A services with respect to the design, operation and use of the search engine (ChatGPT Search) in the UK, and the search content that is presented to users by operation of that search engine. This does not constitute a finding that OpenAI OpCo, LLC is required to meet the additional safety duties for the entire chatbot functionality on ChatGPT where that content does not amount to search content.
[2] Feed Deep Dive is a public search engine included on Facebook, which is therefore a combined service. As such, Meta Platforms, Inc. is required to meet the additional safety duties for Category 2A services with respect to the design, operations and use of the search engine (Feed Deep Dive) in the UK, and the search content that is presented to users by operation of that search engine. This does not constitute a finding that Meta Platforms, Inc. is required to meet the additional safety duties for the entire Feed Deep Dive functionality on Facebook where that content does not amount to search content.
Category 2B threshold conditions are met by a regulated user-to-user service where, in respect of the user-to-user part of that service, it:
- has an average number of monthly active United Kingdom users that exceeds 3 million, and
- provides a functionality for users to send direct messages to other users of the same service which is designed so that messages cannot be encountered by any other users of that service unless further action is taken by the user who sent the message or a user who received the message.
| Service name | Service description | Service provider |
|---|---|---|
| Airbnb | Regulated user-to-user service – Online marketplace (accommodation) | Airbnb Ireland Unlimited Company |
| Autotrader | Regulated user-to-user service – Online marketplace (automotive) | Auto Trader Limited |
| Discord | Regulated user-to-user service – Messaging and chatroom service | Discord Inc. |
| eBay | Regulated user-to-user service – Online marketplace | eBay (UK) Limited |
| Etsy | Regulated user-to-user service - Online marketplace | Etsy, Inc |
| Fortnite | Regulated user-to-user service – Gaming service | Epic Games, Inc. |
| Genius | Regulated user-to-user service – Information sharing service (music) | MediaLab AI, Inc. |
| Google Messages | Regulated user-to-user service of a combined service – Messaging service | Google LLC |
| Gumtree | Regulated user-to-user service – Online marketplace | Gumtree.com Limited |
| Indeed | Regulated user-to-user service – Online marketplace (jobs) | Indeed UK Operations Limited |
| iMessage | Regulated user-to-user service – Messaging service | Apple Distribution International Limited |
| Messenger | Regulated user-to-user service of a combined service – Messaging service | Meta Platforms, Inc. |
| Mumsnet | Regulated user-to-user service – Discussion forum | Mumsnet Limited |
| Nextdoor | Regulated user-to-user service – Social media service | Nextdoor Europe UK Ltd |
| SoundCloud | Regulated user-to-user service – Audio streaming service | SoundCloud Global Limited & Co. KG |
| Pornhub | Regulated user-to-user service – Pornography service | Aylo Freesites Ltd |
| Steam | Regulated user-to-user service – Gaming service | Valve Corp. |
| Strava | Regulated user-to-user service – Fitness tracking service | Strava, Inc. |
| Twitch | Regulated user-to-user service – Livestreaming service | Twitch UK Limited |
| Uber Eats | Regulated user to user service – Online marketplace (food/goods delivery) | Uber Eats UK Limited |
| Vinted | Regulated user-to-user service – Online marketplace | Vinted Limited |
| xHamster | Regulated user-to-user service – Pornography service | Hammy Media Limited |
| xvideos.com | Regulated user-to-user service – Pornography service | WebGroup Czech Republic, a.s. |
| Xbox Network (‘Xbox’) | Regulated user-to-user service – Gaming service | Microsoft Ireland Operations Limited |
List of emerging Category 1 services
The list of emerging Category 1 services is a list of regulated services that meet 75% of the user number conditions for category 1 and at least one of the relevant functionality conditions. Services that are on this “list of emerging category 1 services” do not have additional duties under the Act.
The list of emerging Category 1 services is a list of regulated services that meet the following conditions:
- The first condition is that the number of UK users of the user-to-user part of the service is at least 75% of the figure specified in any of the Category 1 threshold conditions relating to number of users, namely 25.5 million (75% of 34 million) or 5.25 million (75% of 7 million); and
- The second condition is that:
- at least one of the Category 1 threshold conditions relating to functionalities of the user-to-user part of the service is met; or
- if the Regulations specify that a Category 1 threshold condition relating to a functionality of the user-to-user part of the service must be met in combination with a Category 1 threshold condition relating to another characteristic of that part of the service or a factor relating to that part of the service, at least one of those combinations of conditions is met.
| Service name | Service description | Service provider | Category 1 threshold condition(s) by reference to which the service is included |
|---|---|---|---|
| iMessage | Regulated user-to-user service – Messaging service | Apple Distribution International Limited | 34 million monthly active United Kingdom users. |
| Messenger | Regulated user-to-user service of a combined service – Messaging service | Meta Platforms, Inc | 34 million monthly active United Kingdom users. |
| Threads | Regulated user-to-user service – Social media service | Meta Platforms Inc. | 7 million monthly active United Kingdom users + content recommender system + forward or share functionality |
| Wikipedia | Regulated user-to-user service – Information sharing service (encyclopedia) | Wikimedia Foundation, Inc. | 34 million monthly active United Kingdom users |
More information
What is the register?
The published register of categorised services sets out which services are categorised and are therefore subject to additional duties under the Online Safety Act. There are three categories of service – Category 1, Category 2A and Category 2B. The additional duties are set out above.
A service is added to the register where they meet any one or more of the Category 1, Category 2A and Category 2B threshold conditions. The threshold conditions are set out in the Online Safety Act 2023 (Category 1, Category 2A and Category 2B Threshold Conditions) Regulations 2025.
- 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:
- has an average number of monthly active United Kingdom users that exceeds 34 million, and uses a content recommender system; or
- has an average number of monthly active United Kingdom users that exceeds 7 million, uses a content recommender system, and provides a functionality for users to forward or share regulated user-generated content on the service with other users of that service.
- Category 2A threshold conditions are met by a regulated search service or a combined service where, the search engine:
- has an average number of monthly active United Kingdom users that exceeds 7 million, and
- is not a search engine which (i) only enables a user to search only selected websites or databases in relation to a specific topic, theme or genre of search content, and (ii) is facilitated by means of a relevant arrangement.
- Category 2B threshold conditions are met by a regulated user-to-user service where, in respect of the user-to-user part of that service, it:
- has an average number of monthly active United Kingdom users that exceeds 3 million, and
- provides a functionality for users to send direct messages to other users of the same service which is designed so that messages cannot be encountered by any other users of that service unless further action is taken by the user who sent the message or a user who received the message.
What is the list of emerging Category 1 services?
The list of emerging Category 1 services is a list of regulated services that meet the conditions set out in section 97 of the Online Safety Act, by reference to the Category 1 threshold conditions in the Regulations. Applying those conditions to the Category 1 thresholds conditions, we have placed services that meet either of the following sets of conditions on the list:
- the service has 25.5 million monthly average active UK users; or
- the service has 5.25 million monthly average active UK users, uses a content recommender system and provides a functionality for users to forward or share regulated user-generated content on the service with other users of that service.
Services that are on the list of emerging Category 1 services do not have additional duties under the Online Safety Act.
How have services been categorised?
Ofcom has conducted assessments of services we considered likely to meet the relevant threshold conditions outlined above.
We have relied on the best evidence available to us to make those assessments, including using our information gathering powers to request relevant information from providers regarding the scope, functionalities, characteristics and user numbers of their services. In addition to this, we have used information gathered through our own internal research and other available evidence to support our assessments where appropriate.
We provided services providers with our provisional decisions in March 2026 and invited representations from providers. We have taken providers’ representations into account before finalising our decisions.
We have issued service providers with our final decisions, which set out our full assessment of their services against the categorisation threshold conditions.
How often will the register and list be updated?
Ofcom is required to keep the register and list updated and services may be assessed and added to or removed from the register or list as part of a future update. We will update this page to explain more about how this will be done in due course.
Can a service request removal from the register?
Under section 96 of the Online Safety Act, providers of services included in the register may at any time after publication request Ofcom to remove entries relating to that service from the register, or from a particular part of the register. If we are satisfied, on the basis of evidence submitted by a provider with such a request, that since the registration day there has been a change to the service or to regulations under paragraph 1 of Schedule 11 which appears likely to be relevant, we must assess the service and notify the provider of our decision. If Ofcom concludes that the service no longer meets the relevant threshold conditions, Ofcom must remove the corresponding entries from the register.
Categorised services are required to comply with a range of additional duties, depending on which category they fall into. These additional requirements are largely focused on bringing an appropriate level of safety, transparency, and accountability to the online world, reflecting the nature of such services. More details of these duties and which services they will apply to is included in the table below.
We are consulting on the additional duties relating to fraudulent advertising, terms of service, complaints, user empowerment, user identity verification, news publisher content, journalistic content, and content of democratic importance. This consultation will not cover transparency reporting, deceased child user duties, the additional risk assessment duties, or the enhanced record keeping duties as these duties have already been consulted on. More information can be found here.
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