What is CityFibre? The UK's Third National Network
Understanding CityFibre and how it challenges the Openreach monopoly.
The Broadband Landscape is Changing
For decades, the UK broadband market has been effectively a duopoly. You had Openreach (owned by BT but functionally separate), which provided the copper telephone wires that almost every ISP—Sky, TalkTalk, Plusnet, EE—used to deliver service. Then you had Virgin Media, which operated its own cable network in major towns and cities. If you lived outside a Virgin area, you had exactly one choice of infrastructure: Openreach.
This lack of infrastructure competition is one of the main reasons why the UK lagged behind other European nations in the rollout of “Full Fibre.” While countries like Spain and Portugal were digging up their streets to lay fibre optic cables, the UK was sweating its assets, trying to squeeze a few more Megabits out of decades-old copper wires.
Enter CityFibre. Founded in 2011, CityFibre set out with a simple but audaciously expensive mission: to build a brand new, third national infrastructure platform. They aren’t just upgrading old wires; they are digging new trenches, laying new ducts, and blowing new fibre optic cables into millions of homes. They are currently the UK’s largest alternative network (AltNet), with a target of reaching 8 million homes—roughly a third of the UK market.
A Wholesale-Only Model
It is crucial to understand that CityFibre is a wholesale-only operator. You cannot buy a broadband package from CityFibre directly. You will never receive a bill from them. Their job is solely to build and maintain the physical network—the “pipes” in the ground.
They then rent these pipes to Internet Service Providers (ISPs), who are the ones that sell you the service, send you the router, and handle your customer support. This “Open Access” model is transformative. Understanding the difference between wholesale and retail broadband is key to seeing why this benefits you. On Virgin Media’s network, only Virgin can sell you broadband. On CityFibre’s network, dozens of ISPs compete for your business on the exact same wire.
This structural competition drives down prices and drives up service quality. It allows smaller, agile ISPs like Zen Internet, Giganet, and BrawBand to compete on a level playing field with giants like Vodafone and TalkTalk. If one provider offers poor service, you can switch to another CityFibre provider usually within 24 hours, often without an engineer needing to visit, because the physical line is already there.
The Technology: Gigabit City Vision
CityFibre’s network is designed for the future. While Openreach has to manage a complex mix of copper (ADSL), hybrid fibre (FTTC), and full fibre (FTTP), CityFibre has a “clean slate.” They use exclusively Fibre to the Premises (FTTP) technology. We discuss this in more detail in our FTTC vs FTTP guide.
But not all fibre is created equal. CityFibre has deployed XGS-PON (10-Gigabit-capable Symmetric Passive Optical Network) technology across much of its footprint. This means the network is already capable of delivering speeds of up to 10Gbps to residential homes. While most people “only” buy 1Gbps (1000Mbps) packages today, the headroom is there. As 8K streaming, VR/AR, and massive cloud backups become common, the network can handle the load without needing to be dug up again.
By bringing this “Gigabit City” vision to towns like Milton Keynes, Peterborough, Aberdeen, and Coventry, CityFibre has forced the incumbent operators to react. Their presence accelerates the UK’s digital transformation, ensuring we are not left behind in the global digital economy. If you’re considering making the move, our guide on how to switch providers explains how you can do so with zero downtime.