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UK OSA · UK-OSA-COMPLAINTS-APPEALS

UK OSA Section 21 - Duties about complaints procedures (user-to-user)

Operate accessible complaints and appeals procedures covering safety duty compliance and content moderation decisions, with outcome notifications

HIGHProcess dutyUser rightsBinding regulationIn forceApplies from 10 January 2024

Where this comes from

Provision: Section 21 - Duties about complaints procedures (user-to-user); Section 32 (search services)

Instrument: UK Online Safety Act 2023

Citation: Online Safety Act 2023, c. 50, s 21 (including s 21(2A), inserted 29 June 2026) (regulated user-to-user services) and s 32 (regulated search services); s 21 (including s 21(2A), inserted 29 June 2026)(4)(c)-(e) (complaints about take-downs, restrictions and proactive-technology outcomes); s 72(6)-(8) (Category 1 complaints about terms-of-service enforcement). Content reporting is a separate duty under s 20 / s 31 and is carried by UK-OSA-REPORTING.

Text version: Online Safety Act 2023 c. 50, revised text as displayed on legislation.gov.uk on 2026-09-21 ('up to date with all changes known to be in force on or before 21 September 2026'), including the amendments made by the Crime and Policing Act 2026 in force from 29 June 2026 (S.I. 2026/689) and s 66 in force from 7 April 2026 (S.I. 2026/262). The as-enacted text is superseded.

Read the official text ↗

Who it applies to

User-to-user content surface — any one of these:

  • Service allows user-generated content
  • Service enables direct messaging between users

What engineering work it implies

Sample acceptance criteria Landfall generates for this obligation:

  • Notification is sent within required timeframe (check regulation for deadline)
  • Notification content is in plain language, readable by target audience
  • Notification includes: what happened, why it matters, what to do next
  • User can access notification history in their account settings
  • Necessary notification delivery outcomes use scoped references, channel and attempt time without message bodies or extra recipient data

Questions people ask

Does UK OSA Section 21 - Duties about complaints procedures (user-to-user) apply to my service?
It applies when at least one of: Service allows user-generated content; Service enables direct messaging between users.
From when does this apply?
UK OSA Section 21 - Duties about complaints procedures (user-to-user) applies from 10 January 2024. Its current status is: in force.

Find out whether this one lands on you

Landfall's pre-scan answers the applicability question above for your product in minutes, then turns every obligation that applies into traceable engineering tickets with a citation chain your auditors can follow.

Run the pre-scanAll UK OSA obligations

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