The Openreach Network Explained: How the UK Broadband Infrastructure Works

What Openreach is

Openreach builds and maintains the largest access network in the UK, the physical infrastructure that carries broadband and phone connections to the majority of premises. It does not sell broadband directly to the public. Instead, it provides wholesale products to retail providers, which package and sell services to households and businesses. This is why an engineer working on a connection for many different broadband brands may be from Openreach, even though the customer's contract is with the retail provider.

Because so many providers rely on the Openreach network, its reach, reliability and rollout pace shape the broadband experience for a large share of the country. Understanding how it is built helps explain why availability and speeds vary from one address to another.

The physical infrastructure

The Openreach network is made up of several physical elements. Underground ducts carry cables beneath streets and pavements. Telegraph poles carry overhead lines to many premises, particularly where underground routes are impractical. Green street cabinets house the powered equipment used for fibre to the cabinet. Local exchanges are the buildings where lines from many premises are brought together and connected onward into the wider network. Full fibre adds new fibre cables along these same duct and pole routes, running all the way into the premises.

This mix of ducts, poles, cabinets and exchanges is the result of decades of building, and reusing it is central to how fibre is now being rolled out. Pulling new fibre through existing ducts or stringing it along existing poles is faster and cheaper than digging entirely new routes.

Wholesale products

Openreach sells a range of wholesale products that retail providers turn into consumer packages. These include fibre to the cabinet for part-fibre connections, SOGEA for broadband without an analogue phone line, and full fibre for the fastest services. Each product defines what the underlying connection can deliver, while the retail provider adds pricing, customer service, the router and any extras. The wholesale charges Openreach can levy are subject to Ofcom oversight where significant market power applies, which feeds through to the prices consumers pay.

Separation from BT retail

Openreach is a legally separate company within BT Group, with its own board and governance. This separation, overseen by Ofcom, is designed to ensure that every retail provider, including BT's own retail arm, can buy wholesale access on equal terms. The arrangement aims to prevent the network operator from favouring any one provider, which supports fair competition across the retail market. For consumers, it means the choice of retail provider does not usually change who maintains the underlying line.

Wayleaves and access

Installing and maintaining the network often requires crossing land that Openreach does not own. A wayleave is the legal permission to run cables or equipment across or under someone else's land, such as a landlord's property or shared land in a block of flats. Wayleaves can be a practical hurdle for full fibre installation, particularly in flats and multi-occupancy buildings, where agreement from the building owner may be needed before fibre can be brought in. Ofcom and government have taken steps over time to make access easier, but the need for permission remains a real factor in some installations.

How Openreach installs fibre

Full fibre installation typically reuses existing infrastructure where possible. Fibre is pulled through ducts or run along poles to reach a connection point near the premises, then brought into the home and terminated at an Optical Network Terminal. Where ducts are blocked or poles are unsuitable, additional civil work may be needed, which can affect timing. Once fibre has been built past a property, connecting it is usually a matter of the in-home installation. This staged approach, building past premises first and connecting on demand, is how large-scale rollout is managed efficiently.

Faults and who fixes them

Because Openreach maintains the access network, faults on the line itself are usually resolved by Openreach, even though the customer deals only with their retail provider. When a fault is reported, the provider raises it with Openreach where the problem lies outside the home, and an Openreach engineer may be sent to investigate the line, cabinet or external connection. Faults inside the property, such as a problem with the router or internal wiring, are generally the household's responsibility. This division explains why a single fault can sometimes involve both the provider and a network engineer, and why the provider remains the point of contact throughout.

The split also affects compensation. Where a participating provider owes Ofcom automatic compensation for a prolonged loss of service or a missed appointment, the customer claims through the provider, regardless of whether the underlying cause sat in the Openreach network. The regulatory protections attach to the retail relationship, while the physical repair may be carried out by the network operator.

Why the Openreach model matters

The combination of a shared access network and many competing retail providers is a defining feature of the UK market. It allows competition on price and service over a single national network, while the structural separation of Openreach is intended to keep that competition fair. The same model shapes the full fibre rollout, because building past premises once and then letting many providers sell over the new fibre spreads the benefit of the investment widely. For households, the practical result is choice of provider over a network whose reach and upgrades affect a large share of the country.

Frequently Asked Questions

Who owns Openreach?

Openreach is a legally separate company within BT Group, with its own board and governance. The separation is overseen by Ofcom and is designed so that all retail providers, including BT's own retail arm, can buy wholesale access on equal terms.

Can any ISP use the Openreach network?

Retail providers can buy wholesale products from Openreach, such as fibre to the cabinet, SOGEA and full fibre, and sell services over the network. This is why many different broadband brands deliver connections over the same Openreach infrastructure. Because Openreach must offer access on equal terms under Ofcom oversight, providers compete on price, service and contract terms rather than on the underlying line.

What is a wayleave?

A wayleave is the legal permission to run cables or equipment across or under someone else's land. It is often needed to install fibre, particularly in flats and multi-occupancy buildings, where agreement from the building owner may be required before fibre can be brought in.

What is the difference between Openreach and BT Broadband?

Openreach builds and maintains the access network and sells wholesale access to providers; it does not sell to the public. BT Broadband is a retail provider that sells consumer packages, using the Openreach network like other providers. They are separate parts of BT Group.

How does Openreach install fibre?

Full fibre installation typically reuses existing ducts and poles to reach a connection point near the premises, then brings fibre into the home and terminates it at an Optical Network Terminal. Where ducts are blocked or poles unsuitable, extra civil work may be needed, which can affect timing. Once fibre has been built past a property, connecting it is usually a matter of the in-home installation rather than a fresh build.

Does Openreach cover the whole UK?

Openreach operates the largest UK access network and reaches the majority of premises, but coverage of the newest technology varies by area as full fibre rollout continues. In the Hull area, the local network has historically been operated by KCOM rather than Openreach. An availability check shows what the Openreach network can deliver to a specific address.