What the CMA Decision on nexfibre and Netomnia Means for Your Broadband

A merger investigation sounds like something that happens to companies rather than to you, and mostly that is right. But this one decides who owns the network under around 3.4 million homes and who bills around half a million YouFibre customers, and the answer arrives on a known date. This guide sets out what the CMA is deciding, what has been frozen while it decides, what the two sides and the rivals have actually told it, and what each of the three possible outcomes would mean for the person paying the bill.

What is the CMA actually deciding, and when?

Direct answer: whether the deal may be expected to result in a substantial lessening of competition in any UK market, and if so what to do about it. The statutory deadline is Tuesday 15 December 2026, and the CMA has published a timetable with the milestones on the way.

The reference was made on 1 July 2026 under section 33(1A) of the Enterprise Act 2002, and an inquiry group of four CMA panel members, chaired by Cyrus Mehta, will decide it. The question is set by section 36 of the Act. First, whether the deal creates a relevant merger situation, which the parties accept it does, since Substantial's UK turnover was £104 million in the 2025 financial year. Second, whether that situation may be expected to result in a substantial lessening of competition. The CMA's own areas of focus document says it will engage closely with Ofcom, and that it is mindful of the importance of broadband connectivity to consumers and businesses and will carefully consider the potential impact of the transaction on broadband quality, prices and other relevant factors.

What is the deal?

Direct answer: nexfibre, a joint venture between Liberty Global, Telefonica and the private equity investor InfraVia, agreed on 18 February 2026 to buy Substantial Group for an enterprise value of £2 billion. Liberty Global and Telefonica are also the joint owners of Virgin Media O2, which is why the deal is more than a simple altnet purchase.

Substantial Group owns Netomnia and Brsk, which build and operate full fibre networks, and YouFibre and Brsk ISP, which sell broadband to homes over them. At announcement the group had around 3 million premises served and around 450,000 customers, expected to rise to more than 3.4 million premises and more than 500,000 customers by completion; by August, ISPreview put the figures at around 3.2 million premises and 500,000 customers. Netomnia and Brsk merged in June 2024, and the Brsk brand was folded into YouFibre during the first half of 2026, so for practical purposes the retail customers are YouFibre customers.

The structure splits the network from the customers. nexfibre buys the whole group and sells the retail business, the YouFibre and Brsk brands and their customers, to Virgin Media O2 for £150 million, with the announcement promising customers will continue to receive the same trusted service they know today. Alongside, nexfibre will finance a full fibre upgrade of around 2.1 million Virgin Media premises on the older cable network that sit next to Netomnia's footprint, with the majority expected ready by the end of 2027. Virgin Media O2 pays wholesale fees to use that fibre and to serve its customers within the 2.5 million premises where it already overlaps Netomnia, receives around £1.1 billion in cash and an indirect 15 per cent stake in nexfibre, and commits its customers on 4.6 million overlapping and adjacent premises to the combined network. The owners are putting in £1 billion of new funding, £850 million from InfraVia and £150 million jointly from Liberty Global and Telefonica.

Why did it go straight to Phase 2?

Direct answer: because the parties asked. The fast track procedure, introduced by the Digital Markets, Competition and Consumers Act 2024, lets merging parties request a reference straight to an in-depth investigation, and the CMA accepted the request on 1 July 2026.

It is worth being precise about what that does and does not mean. Normally a Phase 1 review decides whether a deal might substantially lessen competition, and most deals clear there. Asking to skip it gives up that quick exit in return for certainty on timing: a decision this year rather than next. The CMA's decision to refer records that the parties have not conceded the deal reduces competition, and nexfibre's chief executive Rajiv Datta said the company requested the fast track to get to the right answer faster. One analyst's advice to the industry on the day was to cool its jets, and that is fair. A fast track reference is a choice about process, not a finding about the deal.

What is the CMA worried about?

Direct answer: that two networks which compete with each other, and with Virgin Media, will stop. The CMA's areas of focus document says it plans to focus on whether the deal gives rise to horizontal unilateral effects at the wholesale and retail levels, which is competition language for one firm buying a rival and then being able to raise prices or degrade quality on its own.

The document sets out the specific questions. Whether nexfibre and Virgin Media O2 on one side, and Substantial on the other, would have competed to sell wholesale fibre to other providers without the deal. Whether Substantial's presence at the retail level, through YouFibre, affects how hard it competes at wholesale. Whether, if Substantial had offered competitive wholesale terms to other providers, that would have put material pressure on Virgin Media's retail prices. And, because both Virgin Media O2 and Substantial sell to homes and to other providers, whether the merged company might have an incentive to refuse to supply rivals or to worsen its wholesale terms to protect its own retail base. The CMA says it is not currently minded to focus on leased lines for businesses, because Substantial sells very few and nobody has complained. Our guide to Openreach versus the altnets explains why overlap matters so much in this market.

What have the rivals told the CMA?

Direct answer: five companies filed responses to the areas of focus document and the CMA has published all of them. They do not agree with each other, which is the most useful thing about them.

CityFibre opposes the deal outright, and says it wanted Netomnia itself. Its response tells the CMA that the most likely conditions of competition without the transaction would involve CityFibre acquiring Netomnia, or Netomnia continuing independently, and that both of these counterfactuals are materially more competitive than the conditions of competition with the transaction, which would result in a substantial lessening of competition. It sets out three concerns: that in overlap areas the deal is a three to two merger at the wholesale level; that nationally it entrenches an Openreach and Virgin Media duopoly and removes a maverick competitor; and that at retail level Virgin Media and Netomnia constrain each other in overlap areas, with Virgin Media steadily losing customers to altnet-based providers. Its chief executive Simon Holden had earlier said the deal would force hundreds of thousands of Netomnia customers back to Virgin Media O2.

Sky opposes it too, from the position of a provider that buys wholesale access. Sky argues nexfibre and Virgin Media O2 should be assessed as a single economic entity, noting that nexfibre has fewer than 50 employees, all in corporate roles, and relies entirely on Virgin Media O2 to build and run its network. In areas where Netomnia overlaps Virgin Media, which Sky puts at approximately 80 per cent of Netomnia's footprint, it says the deal reduces the number of infrastructure competitors from three to two. Sky adds that the merged group already has a lower-cost route to faster fibre rollout by completing the upgrade of its own cable network, without removing an independent competitor.

Hyperoptic does not oppose it. One of the largest altnets kept its response short, saying it does not currently identify competition concerns that would lead it to oppose the transaction, and that the deal has the potential to support a stronger and more sustainable alternative fibre platform.

Grain agrees on wholesale, disagrees on prices. Grain, which covers around 300,000 premises, told the CMA it broadly agrees with the parties that the combination will enhance wholesale competition, but does not think it will lead to a reduction in retail prices, for the simple reason that retail competition at present is already as intense as it has ever been.

BT argues about how it is regulated. The incumbent's response questions the parties' claim that cost savings will be passed to consumers as lower prices, saying this presupposes effective dynamic competition with Openreach that regulation currently limits. It points out that Openreach cannot offer lower prices in areas of greater competition without Ofcom's consent, cannot bundle or make volume-conditional offers without notifying Ofcom, and must give up to four months' public notice of offers. Read one way, that is an argument about the deal. Read another, it is an argument to Ofcom about Openreach.

The CMA will weigh all of this alongside Ofcom's own view. In its 2026 review of the telecoms market, Ofcom judged that Netomnia was unlikely to become a material constraint in the leased line market before 2031, which is one reason the CMA has set business leased lines aside.

What do the parties say?

Direct answer: that the deal creates a scaled challenger to Openreach that could not otherwise exist, that a material share of the resulting cost savings will be passed to consumers as lower retail prices, and that without it all three companies would invest less, build slower and charge more.

That last point is the most important one for a customer, and it is recorded in the CMA's own document. The parties submit that the current market is not the right comparison, and that absent the transaction each of nexfibre, Substantial and Virgin Media O2 would experience reduced network investment, slower full fibre deployment and higher retail pricing than current conditions suggest. The CMA says its assessment will look at the financial and operational position of each company without the deal, and specifically at whether Substantial would have consolidated with another altnet instead, which CityFibre's response has now put squarely on the table. The parties also argue that the deal creates strong financial incentives to move Virgin Media's cable customers onto fibre, which they present as a clear consumer benefit through higher speeds, lower latency and greater reliability. The CMA will test all of it.

What can change for YouFibre customers before 15 December?

Direct answer: very little, and not by choice. On 17 July 2026 the CMA accepted interim undertakings from Substantial Group under section 80 of the Enterprise Act, designed to prevent any action that might prejudice the investigation. In plain terms, the business is frozen in its pre-deal shape until the CMA decides.

The undertakings are enforceable. Breach without reasonable excuse can attract a penalty of up to 5 per cent of turnover, and supplying false information to the CMA is a criminal offence. The chief executive of Substantial has to sign a compliance statement every two weeks from 30 July, listing any key staff who have left, any interruption to the business lasting more than 24 hours, and any substantial change to customer contracts. So if you are a YouFibre customer and something material changes in your service between now and December, that is not a small thing. It is something a company has certified to a regulator has not happened.

What happens if the CMA clears the deal?

Direct answer: the deal completes, the network passes to nexfibre, and you become a customer of a retail business owned by Virgin Media O2, on your existing contract. The change of owner by itself gives you no right to leave. What happens next depends on whether the new owner changes anything.

Your contract transfers with you. Under Ofcom's rules, any subsequent change to your price or terms requires at least one month's notice and a right to exit without early termination charges, with three exceptions: changes purely to your benefit, purely administrative changes with no negative effect, and changes imposed by law. A change of ownership with your price and terms unchanged is administrative. Our guide to what happens when your provider is bought sets all of this out, including the one month window, and this page does not repeat it.

The thing to watch is specific. YouFibre's own help pages state that on a fixed term contract it will not apply a CPI increase, so the amount you pay will not change during your contract, and its marketing in April 2026 made a point of contrasting that with the annual price rise letters sent by larger providers. The announcement promises the same trusted service. Nobody on either side has said whether the fixed price promise continues for new contracts under Virgin Media O2 ownership. Your existing contract is protected by Ofcom's rules whatever happens. Whether the next one is sold on the same terms is the question, and it is the first thing to look for in any letter that follows completion. Our guide to symmetric broadband covers the other YouFibre feature worth watching, since Virgin Media's cable network does not offer it.

What happens if the CMA clears it with conditions?

Direct answer: the deal completes, but with remedies attached to fix whatever competition problem the CMA found. Remedies can be structural, such as requiring part of the network to be sold to someone else, or behavioural, such as commitments on wholesale terms. If you live in an area where the networks overlap, this is the outcome that could change who owns the fibre under your street.

The CMA's timetable shows what to look for. If an invitation to comment on remedies appears in mid to late October, the CMA has provisionally found a problem and is asking what to do about it. The areas of focus document says the CMA may have regard to relevant customer benefits when considering remedies, and records the parties' claim that the deal brings immediate benefits by increasing competition at the wholesale level. The 80 per cent overlap figure, which both CityFibre and Sky have put to the CMA, is the number that matters here, because a structural remedy would most plausibly bite in areas where Netomnia and Virgin Media both already have a network. A customer in such an area could find the fibre serving them sold to a third party as a condition of the deal, with their retail contract following whichever arrangement the CMA approves.

What happens if the CMA blocks it?

Direct answer: Substantial Group stays independent, YouFibre stays as it is, and the interim undertakings fall away. That is not the same as nothing happening, and both the CMA's document and CityFibre's response explain why.

The parties' case is that without the deal, each company faces reduced investment, slower build and higher prices. The CMA has said it will examine the financial and operational position of each of them absent the transaction, and whether Substantial would instead have merged with a different altnet. CityFibre has answered that question for it: its response says the most likely alternative is CityFibre buying Netomnia, and ISPreview reports CityFibre had been trying to do exactly that before the nexfibre deal was announced. The wider altnet market has been consolidating, sometimes through takeovers by lenders rather than buyers, and our consolidation report sets out the pattern. So a block leaves YouFibre customers with the provider they have today, and with a plausible next buyer already on record. The honest position is that a block is the outcome with the least certainty attached to it, not the most.

How do the three outcomes compare?

Direct answer: side by side, they differ on who owns the fibre, who bills you, and how much is settled. This is the table to keep.

What should you watch for, and when?

Direct answer: four documents and one letter. The CMA's interim report in early October, any remedies consultation later that month, the final report in early December, and then, if the deal completes, the letter from your provider telling you what has changed.

What are your rights either way?

Direct answer: the same as before the deal was announced. Your existing contract binds whoever owns the company. A change to your price or terms that is not purely beneficial, administrative or required by law gives you one month's notice and a penalty-free exit. And once your minimum term ends, you can leave for any reason and the switch is handled for you.

Two practical points. If you are out of contract with YouFibre, nothing about this investigation should stop you comparing what else is available at your address, and if you find something better the One Touch Switch process means your new provider arranges the move. And if you are in contract and happy, the sensible thing is to do nothing until December, because the undertakings mean the service you have is the service you keep, and any change after completion comes with a letter and a window.

Where does this leave you?

Direct answer: it depends on one fact about you, which is whether you are still inside a minimum term. If you are, the right move is to wait. If you are not, the right move is to look.

Frequently asked questions

What is the CMA deciding about nexfibre and Netomnia?

Whether nexfibre, a joint venture owned by Liberty Global, Telefonica and InfraVia, can buy Substantial Group, which owns the Netomnia and Brsk fibre networks and the YouFibre and Brsk retail brands. Liberty Global and Telefonica also own Virgin Media O2. The CMA must decide whether the deal may be expected to substantially lessen competition in any UK market, and if so what to do about it.

When will the CMA decide on the nexfibre Netomnia deal?

The statutory deadline is Tuesday 15 December 2026. The CMA's published timetable expects an interim report in early October, a consultation on possible remedies in mid to late October if needed, hearings in late October and early November, and a final report in early December. The deadline can be extended in limited circumstances, but the parties asked for a fast track precisely to avoid that.

Who owns YouFibre now, and who would own it after the deal?

YouFibre is owned by Substantial Group, whose sellers include funds run by DigitalBridge, Advencap and Soho Square Capital. If the deal completes, nexfibre buys the whole group for an enterprise value of £2 billion and sells the retail business, including the YouFibre and Brsk brands and around half a million customers, to Virgin Media O2 for £150 million. The network would belong to nexfibre and the customers to Virgin Media O2.

Will my YouFibre contract change before the CMA decides?

It should not, beyond ordinary day to day business. On 17 July 2026 the CMA accepted interim undertakings from Substantial Group under which it must not integrate with nexfibre, must maintain and preserve the nature, range and quality of its services, must run on its pre-deal business plans, must not change key staff, and must report any substantial changes to customer contracts to the CMA. The chief executive certifies compliance every two weeks.

Will YouFibre's no mid-contract price rise promise survive the deal?

Nobody has said. YouFibre's own help pages state that on a fixed term contract it will not apply a CPI increase, so the amount you pay will not change during your contract. The announcement says customers will continue to receive the same trusted service they know today. Whether the fixed price promise continues for new contracts under Virgin Media O2 ownership is the single most important thing for YouFibre customers to watch, and the article explains what protects the contract you already have.

What have rivals told the CMA about the deal?

They disagree with each other. CityFibre, which had been trying to buy Netomnia itself, says the deal is a three to two merger at the wholesale level in overlap areas and would entrench an Openreach and Virgin Media duopoly. Sky says it reduces infrastructure competitors from three to two across roughly 80 per cent of Netomnia's footprint. Hyperoptic does not oppose it. Grain agrees it enhances wholesale competition but doubts it will cut retail prices. BT argues mainly that regulation limits how Openreach can respond.

What happens to YouFibre customers if the CMA clears the deal?

Your contract transfers to the new owner unchanged, and a change of ownership on its own does not give you a right to leave. If the new owner later changes your price or terms, Ofcom's rules require at least one month's notice and a right to exit without early termination charges, unless the change is purely to your benefit, purely administrative, or imposed by law. Our separate guide on what happens when your provider is bought covers those rights in full.

What happens if the CMA blocks the nexfibre Netomnia deal?

Substantial Group stays independent and YouFibre stays as it is, at least for now. But the CMA's own areas of focus document records that the parties argue that without the deal each of nexfibre, Substantial and Virgin Media O2 would see reduced network investment, slower fibre build and higher retail prices, and CityFibre has told the CMA that the most likely alternative is CityFibre buying Netomnia instead. A block is not the same as nothing happening.

What are remedies, and could they affect my area?

If the CMA finds a substantial lessening of competition, it can allow the deal on conditions rather than block it. Those can be structural, such as requiring part of a network to be sold, or behavioural. CityFibre and Sky have both told the CMA the networks overlap across around 80 per cent of Netomnia's footprint, so any structural remedy would most likely bite in overlap areas. The CMA's timetable allows for a remedies consultation in mid to late October if it gets that far.

Why did the deal skip Phase 1?

Because the parties asked it to. The fast track procedure, introduced by the Digital Markets, Competition and Consumers Act 2024, lets merging parties request a reference straight to an in-depth Phase 2 investigation. The CMA accepted on 1 July 2026. It buys certainty on timing but gives up the chance of a quick Phase 1 clearance. The parties have not conceded that the deal reduces competition.

What does the deal mean for Virgin Media customers?

If it completes, nexfibre will finance a full fibre upgrade of around 2.1 million Virgin Media premises on the older cable network that sit next to Netomnia's footprint, with most expected ready by the end of 2027. Virgin Media O2 will pay wholesale fees to use the fibre, receive around £1.1 billion in cash and an indirect 15 per cent stake in nexfibre, and commit its customers on 4.6 million overlapping and adjacent premises to the combined network.

Does the deal affect Brsk customers?

Yes, in the same way as YouFibre customers. Brsk and Brsk ISP are part of Substantial Group and are named in the CMA's reference. Netomnia and Brsk merged in June 2024, and the Brsk brand was folded into YouFibre during the first half of 2026, so former Brsk customers are YouFibre customers for these purposes and are covered by the same interim undertakings and the same rights.

References

• Bratby Law. (2026, July 1). CMA fast-track Phase 2 reference: nexfibre and Netomnia. Retrieved 5 September 2026, from https://bratby.law/cma-fast-track-phase-2-reference-nexfibre-netomnia/
• Capacity. (2026, July 1). CMA fast-tracks Netomnia deal to Phase 2, sets December deadline. Retrieved 5 September 2026, from https://capacityglobal.com/news/fma-fast-tracks-netomnia-deal/
• Competition and Markets Authority. (2026, July 7). Anticipated acquisition by Liberty Global, Telefonica and InfraVia (through their joint venture, nexfibre) of Substantial: Administrative timetable. GOV.UK. Retrieved 5 September 2026, from https://assets.publishing.service.gov.uk/media/6a4c8afec5aa1b17abab40d0/Administrative_timetable_7_July_2026.pdf
• Competition and Markets Authority. (2026, July 7). Anticipated acquisition by Liberty Global, Telefonica and InfraVia (through their joint venture, nexfibre) of Substantial: Our areas of focus. GOV.UK. Retrieved 5 September 2026, from https://assets.publishing.service.gov.uk/media/6a4c8b1fb7203c4c023fd297/Areas_of_focus_7_July_2026.pdf
• Competition and Markets Authority. (2026, July 24). Undertakings given by Substantial Topco Limited to the Competition and Markets Authority pursuant to section 80 of the Enterprise Act 2002. GOV.UK. Retrieved 5 September 2026, from https://assets.publishing.service.gov.uk/media/6a63457e9a419980593b2b8d/_Interim_undertakings__.pdf
• Competition and Markets Authority. (2026, August 14). nexfibre / Substantial merger inquiry [Case page]. GOV.UK. Retrieved 6 September 2026, from https://www.gov.uk/cma-cases/nexfibre-slash-substantial-merger-inquiry
• ISPreview. (2026, February 19). Netomnia agree UK broadband merger deal with owners of Virgin Media O2. Retrieved 5 September 2026, from https://www.ispreview.co.uk/index.php/2026/02/netomnia-agree-uk-broadband-merger-deal-with-owners-of-virgin-media-o2.html
• ISPreview. (2026, January 11). Netomnia to merge retail UK broadband ISP brand Brsk into YouFibre. Retrieved 6 September 2026, from https://www.ispreview.co.uk/index.php/2026/01/netomnia-to-merge-retail-uk-broadband-isp-brand-brsk-into-youfibre.html
• ISPreview. (2026, July 1). CMA fast tracks nexfibre £2bn Netomnia broadband merger to Phase 2 competition probe. Retrieved 5 September 2026, from https://www.ispreview.co.uk/index.php/2026/07/cma-fast-tracks-nexfibre-2bn-netomnia-broadband-merger-to-phase-2-competition-probe.html
• ISPreview. (2026, August 4, updated August 5). BT, Sky, Grain and Hyperoptic comment on nexfibre's £2bn move to buy Netomnia. Retrieved 6 September 2026, from https://www.ispreview.co.uk/index.php/2026/08/bt-sky-grain-and-hyperoptic-comment-on-nexfibres-2bn-move-to-buy-netomnia.html
• Netomnia. (2026, February 18). Netomnia and nexfibre merger: The UK's largest alternative full fibre platform. Retrieved 5 September 2026, from https://www.netomnia.com/news/netomnia-and-nexfibre-merger/
• nexfibre. (2026, February 18). InfraVia, Liberty Global and Telefonica acquire Substantial Group for £2 billion through their existing joint venture, nexfibre. Retrieved 5 September 2026, from https://www.nexfibre.co.uk/netomnia-news/
• Ofcom. (2025, January). Ofcom's guidance under General Condition C1: Contract requirements. Retrieved 5 September 2026, from https://www.ofcom.org.uk/siteassets/resources/documents/consultations/category-1-10-weeks/272754-consultation-review-of-inflation-linked-telecoms-price-rises/associated-documents/ofcoms-guidance-under-general-condition-c1--contract-requirements-january-2025.pdf
• The Register. (2026, July 1). Brit competition cops fast-track £2B borging of Netomnia into Openreach challenger. Retrieved 5 September 2026, from https://www.theregister.com/networks/2026/07/01/brit-competition-cops-fast-track-2b-borging-of-netomnia-into-openreach-challenger/5264986
• Virgin Media O2. (2026, February 18). InfraVia, Liberty Global and Telefonica acquire Substantial Group for £2 billion through their existing joint venture, nexfibre. Retrieved 5 September 2026, from https://news.virginmediao2.co.uk/infravia-liberty-global-and-telefonica-acquire-substantial-group-for-2-billion-through-their-existing-joint-venture-nexfibre/
• YouFibre. (2024, June 15). Netomnia and Brsk to merge. Retrieved 6 September 2026, from https://www.youfibre.com/news/netomnia-brsk-merger/
• YouFibre. (n.d.). Will you increase my price mid-contract? Retrieved 5 September 2026, from https://support.youfibre.com/knowledge-base/article/will-you-increase-my-price-mid-contract/
• YouFibre. (2026, April 2). How to avoid mid-contract increases. Retrieved 5 September 2026, from https://www.youfibre.com/news/broadband-price-rises-april-2026/

Written by Adrian James, Broadband Editor at BroadbandSwitch.uk (LinkedIn). Reviewed by Dr Alex J. Martin-Smith (LinkedIn). Published 6 September 2026, last verified 6 September 2026. This is a live investigation and the position will change; the CMA case page is the authoritative record. This guide is information, not advice, and nothing in it predicts the outcome. BroadbandSwitch.uk has no commercial relationship with any party to the transaction.