CMA Raises Concerns Over the nexfibre–Netomnia Deal

The Competition and Markets Authority (CMA) says nexfibre’s planned acquisition of Substantial, the group behind Netomnia and YouFibre, may substantially lessen competition in wholesale fixed broadband. The finding, released on 2 October 2026, is provisional. The CMA has not blocked the transaction or made a final decision.

The concern is about the terms on which internet providers can buy access to fibre networks. Less pressure between network owners could ultimately mean weaker deals for households and businesses, the CMA says.

The CMA is comparing the proposed nexfibre purchase with what it believes would most likely happen without this deal. Its provisional view is that CityFibre would have acquired Substantial’s network and sold the retail business to a separate ISP. That is a regulatory assessment of a possible alternative, not an agreed CityFibre takeover.

On that comparison, CityFibre and nexfibre/Virgin Media O2 would have competed to supply other broadband providers in places where their networks overlap. Under the proposed deal, the Netomnia network would instead join nexfibre. For a plain-English explanation of the underlying business model, see our guide to the nexfibre–Netomnia merger and CMA investigation.

The companies argue that combining their networks would support investment and create a stronger wholesale challenger to Openreach. They also say it could speed Virgin Media O2’s move from cable to full fibre.

The CMA acknowledges some extra scale, but provisionally finds that the claimed benefits are either insufficient to outweigh the competition concern or have not been shown to depend on this particular merger. It notes that Substantial’s network could also have been opened to ISPs under its CityFibre comparison.

Its concern is specific to this transaction and the overlap between these networks. The CMA explicitly says its finding is not a general verdict on all UK altnet consolidation. The original £2bn nexfibre acquisition proposal remains subject to regulatory review.

There is no immediate change to a customer’s connection or contract because of today’s interim report. The announced plan for the retail business to move to Virgin Media O2 is conditional on the deal proceeding. Customers should rely on direct notices from their provider for any eventual change. The earlier Brsk-to-YouFibre retail rebrand is a separate, already completed change.

The parties can respond to the findings and put forward possible remedies. The published timetable gives stakeholders until 23 October to comment, while the CMA’s statutory deadline for its final decision is 15 December 2026. Neither deadline means the acquisition automatically completes on that date.