CMA Phase 2 Inquiry into nexfibre's Acquisition of Substantial Reaches Areas-of-Focus Response Stage, with Statutory Deadline Set for December 2026

The Competition and Markets Authority (CMA) is conducting an in-depth Phase 2 investigation into the anticipated acquisition by nexfibre, a joint venture owned by Liberty Global, Telefónica, and InfraVia, of Substantial (which operates through the brands Netomnia, Brsk, Brsk ISP, and YouFibre). The CMA referred the deal for Phase 2 review on 1 July 2026 at the merging parties' own request, using the fast-track procedure available to parties who wish to accelerate scrutiny. An inquiry group chaired by Cyrus Mehta, and including Robin Cohen, Ashleye Gunn, and Crispin Wright, was appointed on the same date, and the statutory deadline for the investigation is 15 December 2026. The Phase 2 inquiry is now at an advanced stage. An Areas of Focus document, which sets out the inquiry group's initial theories on what might be harming competition, was published on 7 July 2026 and attracted responses from third-party stakeholders including BT Group, CityFibre, Sky, Grain Connect, and Hyperoptic, all of which submitted written representations. The merging parties filed their own joint response on 14 August 2026. Interim undertakings were accepted from Substantial on 17 July 2026 under section 80 of the , to preserve the competitive structure of the business during the review. Liberty Global and Telefónica are the joint owners of and, together with InfraVia, co-own nexfibre. Substantial's combined Netomnia network reached approximately 3 million premises as of December 2025, with around 445,000 customers connected. The transaction, if cleared, would consolidate two significant UK full-fibre (FTTP, meaning fibre-to-the-premises) networks under nexfibre's ownership at a time when the UK broadband infrastructure sector is highly competitive and heavily scrutinised by the regulator.