and 2B apply to regulated user-to-user services; applies to regulated search services or the search engine of a combined service.
A provider should monitor the thresholds, but Ofcom makes the formal decision. The first register was published on 30 June 2026 and most recently updated on 28 September 2026.
A is a Part 3 service that Ofcom has entered on its register after assessing the specified scale and functionality conditions. Categorisation comes after Part 3 scope and does not trigger the core illegal-content, children's access, child-safety, reporting, complaints, or record-keeping duties. Calculate each threshold against the regulated service part, then use Ofcom's register for formal status.
1
Section 1
Which category thresholds and calculation rules apply?
has two routes. A regulated user-to-user service qualifies if its user-to-user part exceeds 34 million average monthly and uses a , or exceeds 7 million and both uses a recommender and lets users forward or share regulated user-generated content with other users of the service.
covers a regulated search service or a combined service whose search engine exceeds 7 million average monthly . The threshold excludes a search engine that only searches selected websites or databases on a specific topic, theme, or genre and is facilitated by a relevant arrangement; both parts of that exception must be satisfied.
covers a regulated user-to-user service exceeding 3 million average monthly where direct messages cannot be encountered by other users unless the sender or recipient takes further action. The design of the messaging function, not its marketing name, controls.
For all three categories, calculate the mean number of per month over the six months ending with the month before the assessment starts. Use the shorter operating period if the service has operated for less than six months. A number equal to the threshold does not meet wording that requires the number to exceed it.
The first register shows why the service boundary matters. ChatGPT Search is , but Ofcom states that this does not categorise unrelated chatbot content that is not search content. Facebook appears through different regulated parts, and services such as WhatsApp appear in while many marketplaces and messaging services appear in . These entries illustrate Ofcom's decisions; they do not classify another service by analogy.
Use the regulated user-to-user or search part as the measurement boundary.
Document the active-UK-user definition, data sources, deduplication, and six monthly figures.
Capture current recommender, forward-or-share, direct-message, and search design evidence.
Compare the internal analysis with Ofcom's register; do not label the service formally categorised based only on an internal calculation.
Formal register published on 30 June 2026 and most recently updated on 28 September 2026, with category entries, service-part descriptions, providers, and threshold explanations.
2
Section 2
Who maintains the user counts and functionality evidence?
A data owner should maintain the monthly active UK user calculation. Engineering and product owners should attest to the relevant functionality, and the regulatory owner should map Ofcom's decision to the correct service part and additional duties.
Preserve the six-month data extract, metric definition, service-boundary rationale, functionality specifications and user journeys, internal threshold conclusion, register entry, Ofcom information requests, and any representations made during assessment.
Separate user counts for the user-to-user part from users who only use another part of a combined service.
Explain how logged-out users, multiple accounts, automated traffic, and cross-device duplication are handled.
Version the recommender, sharing, messaging, and search evidence used for each calculation.
Assign an owner to monitor Ofcom's register, , information requests, and category-specific deadlines.
Binding Ofcom duties to assess services, create and maintain the register, and identify emerging Category 1 services.
3
Section 3
How do combined services and emerging Category 1 listings differ?
One product can appear in more than one category because the category attaches to a regulated service part. Formal status for a public search engine does not extend the Category 2A duties to unrelated chatbot, publishing, or user-to-user functions unless those functions fall within the categorised search service.
The is not the register. It uses the Act's 75% user-number conditions and specified functionality to flag services that may soon meet a Category 1 threshold. The current user-number markers are 25.5 million, or 5.25 million where the recommender and forward-or-share conditions also apply; listed services do not acquire the additional Category 1 duties.
If the same user-to-user service meets both and conditions, the Act treats it as Category 1 and Ofcom enters it only in the Category 1 part of the register.
A public search engine within a combined service can be even when the user-to-user part is not categorised, and the reverse is also possible.
Do not treat the topic-specific exception as a Part 3 scope exemption or apply it to general search functions.
Do not wait for categorisation to complete illegal-content or child-safety work; those duties follow Part 3 scope and risk, not category.
Primary source distinguishing core Part 3 duties from the additional duties for categorised services.
4
Section 4
How should teams implement a formal categorisation decision?
Once Ofcom places a service on the register, map the statutory additional duties to the registered part and current commencement position. includes duties concerning user empowerment, identity verification, democratic-importance content, news publisher content, journalistic content, terms, complaints, and freedom-of-expression and privacy assessments.
and 2A services have fraudulent-advertising duties and duties to provide specified risk-assessment records to Ofcom. Category 1, 2A, and 2B services can also have transparency-reporting and fee obligations. Check the current Ofcom notices, codes, and commencement position for each deliverable rather than assuming one common deadline.
For and 2A services, update the risk-assessment record to reflect the registered service boundary and Ofcom's current request for records by October 2026.
Create a category-duty register with the legal section, service part, owner, evidence, current regulatory document, commencement status, and due date.
Label Ofcom consultations and draft codes as proposals until issued or otherwise brought into effect.
Recalculate and review after material user growth or functionality changes even when the formal register has not yet changed.
Formal status and registered service boundaries to use when assigning the additional duties.
Recommended next step
Assign the duties for the registered service part
Connect the six-month UK-user calculation, functionality evidence and Ofcom register entry to category-specific owners, commencement checks and deliverable dates.
Official register published on 30 June 2026 and most recently updated on 28 September 2026, with threshold summaries, service-part decisions, and the emerging Category 1 list.
Formal register published on 30 June 2026 and most recently updated on 28 September 2026, with category entries, service-part descriptions, providers, and threshold explanations.
Official examples of multi-category and service-part entries and the separate emerging Category 1 list.
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Formal status and registered service boundaries to use when assigning the additional duties.