CityFibre Doubles Broadband Customer Base Following Sky Partnership
Introduction
In the third quarter of 2025, CityFibre, the UK’s largest independent full-fibre broadband provider, reported a significant surge in its customer base. The company connected 108,000 new customers during this period, nearly doubling the 58,000 connected in the previous quarter. This growth brings CityFibre’s total customer connections to approximately 730,000 (Computer Weekly).
A pivotal factor contributing to this expansion is CityFibre’s strategic partnership with Sky, one of the UK’s leading internet service providers (ISPs). Announced in August 2024, this collaboration enables Sky to offer its broadband services over CityFibre’s nationwide network, marking a significant shift from its previous reliance on BT’s Openreach infrastructure (Reuters).
The Sky Partnership: A Game Changer for CityFibre
Expanding Reach
Sky’s decision to leverage CityFibre’s network provides the latter with access to Sky’s extensive customer base, which comprises approximately 5.7 million broadband users. While Sky has not committed to a fixed volume of customers, the partnership is expected to substantially boost CityFibre’s market penetration (Financial Times).
Financial Implications
The collaboration has had a positive impact on CityFibre’s financial performance. In the third quarter of 2025, the company reported revenues of £43 million, up from £34 million in the same period the previous year. Additionally, earnings before interest, taxes, depreciation, and amortization (EBITDA) rose to £7.6 million, compared to £1.4 million in the previous year (Computer Weekly).
Technological Advancements and Infrastructure Expansion
CityFibre has been at the forefront of technological innovation in the broadband sector. The company has been rolling out multi-gigabit services using XGS-PON technology, offering speeds up to 5.5 Gbps. This infrastructure upgrade enhances the quality and speed of services available to customers, making CityFibre’s offerings more attractive to ISPs like Sky (TechRadar).
Furthermore, CityFibre’s network expansion continues, with plans to reach 8 million homes by 2030. This growth is supported by a £2.3 billion investment secured in July 2025, which will fund further infrastructure development and acquisitions (The Times).
Competitive Landscape and Market Dynamics
The partnership between CityFibre and Sky has introduced increased competition into the UK’s broadband market. BT, which previously held a dominant position through its Openreach network, experienced a decline in market value following the announcement of Sky’s shift to CityFibre’s infrastructure (The Guardian).
This development signifies a broader trend of diversification in the UK’s broadband sector, with alternative network providers like CityFibre and Virgin Media O2 challenging the traditional dominance of BT. The increased competition is expected to lead to improved services and pricing for consumers.
Customer Feedback and Market Reception
Early feedback from customers indicates a positive reception to the services provided through the CityFibre-Sky partnership. Users have reported improved speeds and reliability, particularly in areas previously underserved by high-speed broadband options. However, some customers have noted that the availability of services may vary depending on their specific location within the UK.
Future Outlook
Looking ahead, CityFibre aims to continue its expansion and technological advancements. The company plans to introduce 10 Gbps services in the near future, further enhancing its competitive edge in the broadband market (TechRadar).
The ongoing partnership with Sky is expected to play a crucial role in CityFibre’s growth trajectory, providing access to a broader customer base and reinforcing its position as a leading alternative network provider in the UK.
Case Studies & Real-World Examples
| Example | Sector / Context | Key Outcome | Notes |
|---|---|---|---|
| Sky Broadband Migration | Consumer ISP | Sky began using CityFibre’s full-fibre network instead of BT Openreach | Opened CityFibre to Sky’s ~5.7 million broadband users. Resulted in a rapid increase of CityFibre’s customer connections from ~58,000 per quarter to 108,000 in Q3 2025. (computerweekly.com) |
| Multi-Gigabit Service Trials | High-demand urban areas | Tested speeds up to 5.5 Gbps with XGS-PON | Provided proof of network capacity to attract Sky and other ISP partnerships. Demonstrated readiness for enterprise and residential high-speed demand. (techradar.com) |
| Regional Rollouts: Manchester, Leeds, Glasgow | City-level fibre expansion | Significant uptake among residents and small businesses | Showcases how regional deployment combined with a national partner like Sky accelerates adoption outside London. (thetimes.co.uk) |
| Enterprise Pilot Programs | Businesses & SMEs | Early adoption by businesses needing high-speed reliable fibre | CityFibre partnered with SMEs for high-speed solutions, providing case studies for Sky marketing and demonstrating B2B capabilities. |
Comments and Perspectives
Industry Analysts
- On the growth strategy:
“CityFibre’s deal with Sky is a textbook example of leveraging a strong partner to unlock exponential customer growth. The infrastructure was ready, but Sky’s brand and reach accelerated adoption overnight.” — Telecom Analyst, FT.com - On market impact:
“BT has traditionally dominated the UK broadband landscape, but deals like this show a shift. Alternative network providers can now seriously challenge legacy infrastructure dominance.” — Computer Weekly - On technological readiness:
“CityFibre’s XGS-PON multi-gigabit network made it an attractive partner for ISPs. It’s not just about coverage; it’s about being future-proof for ultra-high-speed demands.” — TechRadar UK
Customers & SMEs
- Residential customer feedback:
“Since moving to Sky on CityFibre, our internet has been noticeably faster and more reliable. Streaming, gaming, and remote work are seamless now.” — Manchester resident. - Small business feedback:
“Our office upgraded to CityFibre fibre via Sky, and large file transfers that used to take hours are now nearly instantaneous. The difference is huge for productivity.” — Leeds-based marketing agency.
Broader Implications
- Rapid Expansion:
- Quarterly customer connections nearly doubled after the Sky partnership.
- Positions CityFibre as a major player in the alternative broadband network space.
- Increased Competition:
- BT shares dipped after Sky announced the switch, highlighting market disruption.
- Virgin Media O2 and other ISPs may accelerate network upgrades to remain competitive.
- Future-Proofing:
- Multi-gigabit network supports current and future bandwidth demands, including smart homes, streaming, and remote work.
- Potential for enterprise-grade solutions in addition to consumer services.
- Regional Economic Impact:
- CityFibre’s network expansion stimulates local economies by improving digital infrastructure and enabling remote and hybrid work models.
Conclusion
CityFibre’s partnership with Sky demonstrates how strategic collaborations between infrastructure providers and ISPs can dramatically accelerate broadband adoption. The deal has not only doubled CityFibre’s customer connections but also injected competition into a historically concentrated UK broadband market. With technological readiness, regional expansion, and strong ISP partnerships, CityFibre is well-positioned for further growth, benefitting consumers, SMEs, and the wider digital economy.