The Digital Markets, Competition and Consumers Act 2024 created a new regulatory regime for large tech platforms. From October 2026, the Competition and Markets Authority (CMA) can designate a firm with "strategic market status" (SMS) in a digital activity — a status that triggers a package of conduct requirements and enables bespoke interventions. The first SMS investigations, covering major search, app store, and browser markets, are under way.
Separately, Part 2 of the Act extends class action-style collective proceedings in the Competition Appeal Tribunal (CAT). Businesses that have suffered loss from anti-competitive practices — including price-fixing cartels or abuse of dominance by a platform — can now be included in a collective claim without individually opting in. This significantly widens access to redress for SMEs. The CMA website publishes all open and closed SMS investigations.
For businesses that interact with major platforms — for example, retailers relying on a dominant marketplace or app developers — the new conduct requirements on SMS firms include prohibitions on self-preferencing, tying, and unfair terms. A business that believes a platform is in breach of a conduct requirement can complain to the CMA. See the ICO complaint guide for a parallel regulatory complaint process under data protection law.