When it comes to leased lines in the UK, BT has long been the dominant player. But in recent years, CityFibre has emerged as a powerful challenger, rolling out a rapidly expanding fibre network across dozens of UK cities. If you’re comparing CityFibre vs BT in 2025, here’s what you need to know.
Coverage: National vs City-Based
BT still boasts the UK’s largest nationwide footprint, making it the go-to for businesses outside major towns or cities. Whether you’re in Cornwall, the Highlands, or the Midlands, BT coverage is almost always available.
CityFibre, meanwhile, focuses on over 60 UK cities, with ambitious plans to expand further. If you’re in one of their coverage areas (London, Birmingham, Leeds, Sheffield, Bristol and more), CityFibre often delivers extremely competitive services.
Check instantly which providers cover your postcode with our leased line providers comparison tool.
Speeds: Who Delivers More Capacity?
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BT typically offers leased lines ranging from 100Mb to 10Gb.
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CityFibre goes further, with scalable services up to 100Gb in select locations — making it one of the few carriers in the UK offering ultra-high-capacity connectivity.
If you’re an enterprise with heavy cloud, data, or video needs, CityFibre’s capacity could be a game changer.
Pricing: Who’s More Affordable?
BT’s pricing tends to reflect its scale and reliability, but that doesn’t always mean cheapest.
CityFibre’s aggressive growth strategy means they often price sharply below BT in covered cities. For example, a 1Gb leased line from CityFibre in Manchester or Birmingham can sometimes undercut BT by hundreds of pounds a month.
See BT and CityFibre prices side by side for your address using our instant leased line quote tool.
SLAs & Reliability
Both providers deliver uncontended, symmetrical leased lines with robust uptime guarantees:
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BT: Excellent 24/7 support and nationwide engineering coverage.
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CityFibre: Competitive SLAs, with strong resilience and quick delivery times in urban networks.
In practice, both are reliable. BT may have the edge in rural support, but CityFibre excels in cities with new infrastructure.
Installation & Lead Times
Leased line installs are rarely instant — expect 45–90 days on average.
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BT: Typically smoother outside of cities thanks to their entrenched national infrastructure.
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CityFibre: Faster in many metro areas due to newer, purpose-built networks.
Either way, wayleave permissions and construction requirements can extend timescales.
Read more about leased line installation times.
Best Fit: Which Businesses Should Choose Which?
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Choose BT if: You need coverage in rural areas or across multiple remote sites.
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Choose CityFibre if: You’re in a major UK city and want ultra-fast speeds or lower monthly pricing.
For many businesses, the decision comes down to whether CityFibre is live in your postcode.
Why Compare Both with Connect2?
At Connect2, we partner directly with BT and CityFibre, as well as Virgin, Vodafone, TalkTalk, Colt, Neos, Vorboss, Sky, Elevate and ITS.
When you request a quote, we instantly:
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Check whether CityFibre and BT are available at your location.
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Compare live pricing, speeds and contract terms.
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Show you where free installation is possible.
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Give you impartial advice on the right SLA for your business.
Get your free CityFibre vs BT leased line comparison today.
Final Thoughts
The CityFibre vs BT debate isn’t about who’s “best” overall. It’s about who’s best for your business and your postcode. BT remains the safest choice for nationwide reach, while CityFibre brings speed, scalability and competitive pricing to urban areas.
Instead of guessing, let Connect2 compare both for you — quickly, transparently, and at no extra cost.
Start your leased line provider comparison and see whether BT or CityFibre delivers the best value in 2025.
