How to tell which network your UK broadband provider uses: the retailer to access network map for 2026, and why the brand on your bill no longer answers the question

The short version, and when it matters

Direct answer: The honest answer to which network your provider uses is that it depends on your address, not on your provider, and that nobody is required to tell you either way.

If you want the one-line answer and nothing else: Ask your provider, in writing, which access network your line runs on. They know, the answer costs them nothing, and asking is the only method on this page that works on every network. Everything below is the working, and the reason the working is needed at all is that the obvious methods have stopped returning an answer.

Before any of that, the honest caveat: most households never need this answer, and a section further down sets out the four situations where it genuinely changes something. If none of those four is you, the technology and the price matter more than the name of the network underneath, and the sister guide to this one is the better read. The four technologies are closer on speed than the adverts suggest and further apart on what happens when it goes wrong. That is the comparison worth making, and it is the one nobody puts on the box.

That guide is full fibre against FTTC against cable against 4G and 5G, and it is the one to read if what you actually want to know is which technology to buy. This page is about who owns the wire.

Which retailer sells over which network

Direct answer: Five of the best-known names in UK broadband sell over more than one network, so the brand on your bill does not tell you whose fibre is in the ground outside your house.

The evidence is CityFibre's own published retailer directory, which names 44 providers and carries its own last-updated date. Sky, TalkTalk, Vodafone, Zen and Utility Warehouse are all on it, and all five also sell over Openreach. Sky and CityFibre signed a partnership in August 2024 to put Sky Full Fibre on the CityFibre network, and Sky is named on CityFibre's own retailer list today. CityFibre is VodafoneThree's anchor customer and the two extended the arrangement in June 2026. VodafoneThree also sells over Community Fibre's London network, which Vodafone says reaches up to 1.3 million homes in the capital. Zen's own words: “We've provided broadband over the Openreach network for many years”, and in the same post it describes selling over CityFibre, Trooli and Freedom Fibre as well.

It runs the other way too, and that is the part that catches people who follow this closely. Hyperoptic will continue to expand coverage through its wholesale agreement with Openreach. Those are Hyperoptic's own words. Its own network reaches 1.9 million homes passed, and beyond that it is an Openreach retailer like any other. Hyperoptic publishes nothing telling a customer which of the two networks their own line uses. toob built its own network and also sells over CityFibre, and it appears on CityFibre's own retailer list. And YouFibre is not a network at all, in its own words: “Each week, we connect thousands of new homes across the UK to the network that's built for broadband by Netomnia.”

So the table that used to answer this question has stopped being able to. A retailer with one network has a row. A retailer with three has an address.

Our UK wholesale network matrix tracks who owns which fibre, which providers use Openreach covers that network in detail, and who owns which UK broadband brand covers the ownership behind the names.

Brand by brand, which network each one uses

Direct answer: Five of the eight answers below are more than one network, and in every one of those five cases the company does not tell you which of them you are on.

A pattern worth noticing across those eight: the answer is simple only where the retailer and the network are the same company, or where the retailer has never bought from anyone else. Every time a retailer adds a second network the answer stops being a fact about the brand and becomes a fact about your street.

Our which providers use Openreach page keeps the longer list, and who owns which UK broadband brand covers the ownership behind the names, which is a different question again.

The four networks, and how far each reaches

Direct answer: Openreach reaches 23.4 million premises, Virgin Media O2 passes 16.2 million, CityFibre passes 4.7 million and nexfibre 2.6 million. Reaching a premises is not the same as serving it.

Openreach is the one most households are on, and the gap between its two numbers is the whole story of the last five years: it reaches 23.4 million and has connected 9.4 million, a take-up of 40%. It is building towards 25 million by December 2026. Its older copper-based FTTC still reaches 96% of the country. Openreach does not retail: it sells to between 650 and 690 providers who do, though Openreach's own pages give three different counts of how many providers sell over it, and none of the three pages carries a date.

CityFibre is the largest network with no retail arm at all. CityFibre sells only wholesale. It has no retail brand of its own, so every CityFibre line is sold to you by somebody else. It passes 4.7 million and has over one million connections, and it describes its retail partners as representing around 50% UK broadband market share. CityFibre publishes no recommendation between the providers on its own network, and no ranking of them. Its shareholders are Antin Infrastructure Partners, Goldman Sachs Asset Management, Mubadala Investment Company, Interogo Holding, Newlight Partners and PATRIZIA's European Infrastructure Fund II.

Virgin Media O2 is the only one of the four that is both a network and a big retailer. It passes 16.2 million premises and serves 5.4 million consumer broadband customers, and its full fibre footprint is 9 million, which its own release says includes nexfibre. The rest is still coaxial cable. Virgin Media does not publish how much of its own network is still coaxial and how much is full fibre, and it does not tell a customer which of the two they are on.

Below those four sit the smaller networks, and they matter more than their size suggests because several of them also sell wholesale. Netomnia, Freedom Fibre, G.Network, Gigaclear, OFNL, FullFibre, Connect Fibre and LightSpeed all publish wholesale offers of their own, so on any of them the retailer and the network can be different companies. Fibrus publishes wholesale access only in areas where public funding has been used, which makes it an obligation attached to a subsidy rather than a commercial choice. On a new-build development the network is often neither Openreach nor an altnet you have heard of: OFNL builds wholesale-only fibre on new estates and names around 18 residential retailers on its own site.

Networks also change hands, and when they do the retail brand usually carries on unchanged. CityFibre has grown by buying as well as building: it acquired Lit Fibre in 2024 and Connexin's fibre infrastructure in 2025, and in both cases the retail brand carried on selling while the network underneath changed hands. Even the networks buy from each other. Hyperoptic buys wholesale from Openreach, toob buys from CityFibre, and Connexin now sells over the network CityFibre bought from it. None of that is visible from the outside, which is the recurring theme of this page.

Read more in how UK wholesale broadband works, Openreach against CityFibre, Openreach against the altnets and what altnets are and why they matter.

How to tell which one you are on

Direct answer: Ask your provider, in writing, which access network your line runs on. They know, the answer costs them nothing, and asking is the only method on this page that works on every network.

That is an unsatisfying answer and it is the true one, so it is worth showing the working rather than asserting it. Here is each method in turn, and what it actually tells you.

The box on your wall is the one partial test that works. If a full fibre install left a small white box, look at it: Openreach labels its own. In Openreach's words the unit is an Optical Network Terminal, and “It belongs to Openreach, not your provider, and not you.” The reason it identifies the network rather than the retailer is the useful part: “Because multiple providers use the same Openreach network, it can support whichever provider you're with.” That test works for Openreach and stops there. No altnet publishes an equivalent guide to reading its own box.

Your contract will not tell you. Ofcom's contract summary rules require the speed, the price, the contract length and the exit terms. The network is not on the list. Your bill will not either. Ofcom's own postcode checker is not a reliable answer, in Ofcom's own words: “We only provide the names of network providers that have expressly given permission to include their names and web details on our checker.” Switching provider reveals nothing either, because switching was deliberately made the same whichever network you are moving between. Ofcom's own description: “This means you can switch between different networks or technologies, for example from a provider using the Openreach network to one using CityFibre's, or from Virgin Media to Hyperoptic.” That uniformity is good for you. It just means the process is silent on this question.

Which leaves asking, and it is worth being specific when you do. The phrase that gets a useful reply is access network, because that is the industry's own term for the thing you are asking about, and a retailer's support team will recognise it where they may not recognise a question about who owns the cable. Your provider has to know the answer in order to place the order in the first place, and there is no commercial reason to withhold it. If you are about to move house or about to sign, it is worth the email.

Our One Touch Switch explainer covers how switching works now, and which network are you actually on covers the same confusion on mobile.

Why nobody has to tell you

Direct answer: Ofcom requires your provider to tell you the technology, in four plain words. It requires nobody to tell you the network.

This is not an oversight so much as a boundary nobody has moved. Ofcom looked hard at broadband labelling and concluded that “the term 'fibre' is being applied inconsistently by the telecoms industry and is often used to describe different types of networks, leading to confusion among customers”. Its answer was to require four unambiguous words at the point of sale: cable, copper, full-fibre and part-fibre. That rule has applied since 16 September 2024, it is a genuine improvement, and it means a shopper can no longer be sold a copper line described only as fibre.

But none of those four words is a network. Full-fibre describes a line that could be Openreach's, CityFibre's, Netomnia's or Hyperoptic's, and the rule is satisfied either way. The contract summary rules, set out above, do not carry it either. So there is no point in the sales process, and no document afterwards, where the answer is required to appear.

Our guide to the minimum guaranteed download speed covers what you are entitled to on speed, and up to speed against guaranteed minimum explains the two numbers you will be quoted.

Mobile home broadband, where the network moved under you

Direct answer: On mobile there are now effectively three networks selling home broadband rather than four, because Vodafone and Three merged and O2 does not sell it.

Start with the one that surprises people. O2's own words on its own broadband page: “We don't offer home broadband as O2.” That page sends you to Virgin Media instead. O2 is one of the four mobile networks and is routinely listed as a home broadband seller, and it is not one.

Then the merger. Vodafone and Three are now one company, and the two mobile networks have been joined underneath. Vodafone's own explanation: “Whether your phone has a Vodafone or a Three SIM, it will connect to either a Vodafone or a Three mast, whichever one provides the best signal in your location.” For a phone that is straightforwardly good news, and for a 4G or 5G home broadband router it is the same technology doing the same thing.

The part worth knowing is what the device shows you. In Vodafone's own words, “there won't be any change in the stated name of the network as it appears in your phone's settings or at the top of its screen”. So on mobile, as on fixed lines, the name in front of you is not a reliable guide to the network behind it. The difference is that on mobile the company has published that plainly, which is more than the fixed side manages.

See 5G home broadband deals and 4G home broadband deals as they stand today, or fixed wireless against fibre for the trade-off. What you give up on protections is covered in our technology guide.

Why your provider cares which network you are on

Direct answer: Your retailer chooses the network, and it is paid to care which one. You are not told, and no rule says you have to be.

A retailer buys the line wholesale and sells it to you retail, so the wholesale price is most of its cost. Networks compete for that business with discounts, and the discounts are large enough to be worth a regulator's attention. Ofcom proposed in July 2026 to block a new Openreach discount, worth up to £9.50 a month per customer for up to 30 months, on the ground that it was aimed at exactly the customers smaller networks need in order to grow. Ofcom's consultation on it closed on 27 August 2026 and no final decision had been published when this page was last checked.

Whatever Ofcom decides, the shape of it is the point for a reader of this page: when a retailer can put you on two networks, it has a commercial reason to prefer one, and you have no way to see which reason applied to you. That is not an accusation about any particular company. It is a description of a market in which the buyer cannot see the product.

It also explains why this is worth checking at renewal. CityFibre sells only wholesale. It has no retail brand of its own, so every CityFibre line is sold to you by somebody else. A network with a long list of retailers on it gives you somewhere to go when your price goes up. A network with one gives you the same company under a different name.

Our explainer on the Ofcom discount decision covers what it means for your bill, and altnet economics covers why the smaller networks are merging.

When the answer actually changes something

Direct answer: It matters in three situations and almost nowhere else: when you are deciding whether a switch will need an engineer and a new cable, when you want to know whether a faster package can ever reach you, and when you are weighing how much choice of provider you will have later.

Outside those four situations, the network is trivia. The technology decides what your connection can do and the retailer decides what you pay and who answers the phone, and both of those are published. This page exists for the minority of weeks in a household's life when the third question suddenly matters, and for the fact that in those weeks the answer is unreasonably hard to get.

If you are mid-move, our Virgin Media to Openreach guide and what changes on installation day cover the two most common cross-network switches, and a new build with no Openreach line yet covers the case above.

The map is about to be redrawn

Direct answer: nexfibre is buying Netomnia, and with it YouFibre and brsk. It is in a Phase 2 inquiry, which is the deeper of the CMA's two stages, and it has not completed. The statutory deadline is 15 December 2026.

If it goes through, two of the networks on this page become one, and a YouFibre or brsk customer's network changes owner without their line changing at all. Nothing on this page assumes an outcome, because the decision has not been made, and a Phase 2 inquiry can end in a block, a clearance or a clearance with conditions.

What is already public is who has objected and why, because the CMA publishes the submissions. Sky, BT Group, CityFibre, Hyperoptic and Grain Connect have all filed submissions the CMA has published. Sky's own words: “The CMA should therefore treat nexfibre and VMO2 as a single economic entity for the purposes of its competitive assessment.” CityFibre's: “Competition from VMO2/Nexfibre alone has not been sufficient to constrain Openreach in the past, and will not be sufficient”. Both are arguing that the deal removes a competitor rather than creating one.

For a household the practical question is narrower. If you are a YouFibre or a brsk customer, your line does not change and your service does not change; the company that owns the network behind it might. If you are shopping now in an area where both nexfibre and Netomnia have built, the number of independent networks at your address could fall from two to one. Either way, 15 December 2026 is the date to watch.

Our altnet consolidation tracker follows who has bought whom, and what the CMA decision means for your broadband covers the customer side.

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