# 30 leading Telecommunications companies in London
Tamtam tracks 68 Telecommunications companies headquartered in London. This list ranks the 30 largest by number of employees on LinkedIn, led by Vodafone, BT Group and Openreach. Their median headcount is 1,407. Half of them were founded in 2003 or later.
This selection of telecommunications companies in London includes large established groups and mid-sized firms. Many operate globally or have a significant presence across the UK. Vodafone, for example, uses technology to connect people globally and drive social change, while BT Group is a global communications services company. Openreach focuses on being the UK's digital network business, and EE is a mobile communications company offering extensive network coverage.
A notable pattern among these companies is their focus on comprehensive connectivity and digital infrastructure. Several companies, such as Virgin Media O2 and CityFibre, emphasize providing fast broadband and extensive mobile networks. Colt Technology Services is a global digital infrastructure provider, and IHS Towers specializes in tower infrastructure in emerging markets. This indicates a strong emphasis on foundational network services and expansion.
π¬π§ London Β· 30 companies Β· Updated Nov 12, 2026
| # | Company | Industry | Headquarters | Employees | Founded |
|---|---|---|---|---|---|
| 1 | [Vodafone](https://www.tamtam.ai/c/vodafone) (vodafone.com)
Using technology to connect people globally, drive social change, and improve lives while emphasizing the importance of humanity and collaboration | Telecommunications | π¬π§ London | 142,740 | 1982 |
| 2 | [BT Group](https://www.tamtam.ai/c/bt-group) (bt.com)
A global communications services company connecting people through technology to address challenges like the pandemic, climate change, and cyber security | Telecommunications | π¬π§ London | 73,712 | |
| 3 | [Openreach](https://www.tamtam.ai/c/openreach) (openreach.com)
This company is the UK's digital network business, connecting homes, businesses, and more to the world with a focus on high-quality service | Telecommunications | π¬π§ London | 16,885 | |
| 4 | [EE](https://www.tamtam.ai/c/ee) (ee.co.uk)
A leading mobile communications company in the UK, offering mobile and fixed services with the largest and fastest network coverage | Telecommunications | π¬π§ London | 12,146 | 2012 |
| 5 | [Virgin Media O2](https://www.tamtam.ai/c/virgin-media-o2) (virginmediao2.co.uk)
Provides fastest broadband and largest mobile network in the UK, focusing on customer-first connectivity services and network upgrades. | Telecommunications | π¬π§ London | 8,272 | 2021 |
| 6 | [Vodafone Business](https://www.tamtam.ai/c/vodafone-business) (vodafone.com)
Providing mobile, fixed, unified communications, IoT, cloud, and security services to businesses globally, regionally, and locally. | Telecommunications | π¬π§ London | 8,100 | |
| 7 | [Colt Technology Services](https://www.tamtam.ai/c/colt-technology-services) (colt.net)
Global digital infrastructure provider connecting businesses across 40+ countries with extensive networks, customer-focused innovation, and reliable connectivity solutions. | Telecommunications | π¬π§ London | 5,107 | 1992 |
| 8 | [IHS Towers](https://www.tamtam.ai/c/ihs-towers) (ihstowers.com)
A leading tower infrastructure company with over 40,000 towers in emerging markets, specializing in hybrid energy solutions and network monitoring | Telecommunications | π¬π§ London | 3,497 | 2001 |
| 9 | [Liberty Global](https://www.tamtam.ai/c/liberty-global) (libertyglobal.com)
Global provider of broadband, mobile communications, and infrastructure investing in fibre, 5G networks, content, technology, and innovation. | Telecommunications | π¬π§ London | 2,833 | 2005 |
| 10 | [Gamma](https://www.tamtam.ai/c/gamma) (gammagroup.co)
Gamma is a leading supplier of Unified Communications services in the UK, Germany, Spain, and Benelux, offering robust solutions for communication and collaboration | Telecommunications | π¬π§ London | 2,588 | 2002 |
| 11 | [Telecom Jobs](https://www.tamtam.ai/c/telecom-jobs) (telecomjobs.uk)
The company aims to be the top resource for telecom jobs in the UK by connecting jobseekers and employers in the industry | Telecommunications | π¬π§ London | 2,468 | 2021 |
| 12 | [Senture, LLC](https://www.tamtam.ai/c/senture-llc) (senture.com)
A premier domestic contact center solutions company providing comprehensive service support nationally, focused on delivering excellent customer experiences and award-winning support services | Telecommunications | π¬π§ London | 2,129 | 2003 |
| 13 | [CityFibre](https://www.tamtam.ai/c/cityfibre) (cityfibre.com)
We build open-access fiber networks across the UK, providing fast and reliable broadband, Ethernet, and mobile connections to homes, businesses, and institutions | Telecommunications | π¬π§ London | 1,800 | 2011 |
| 14 | [Ofcom](https://www.tamtam.ai/c/ofcom) (ofcom.org.uk)
Regulating UK communications, ensuring fair home phone and mobile services, overseeing TV, radio, and content, protecting consumers, promoting access to technology | Telecommunications | π¬π§ London | 1,700 | 2003 |
| 15 | [GSMA](https://www.tamtam.ai/c/gsma) (gsma.com)
Global organization uniting mobile ecosystem to drive innovation, connectivity, and societal change Delivers industry solutions, connectivity efforts, and leading events worldwide | Telecommunications | π¬π§ London | 1,407 | |
| 16 | [Lyca Mobile UK](https://www.tamtam.ai/c/lyca-mobile-uk) (lycamobile.co.uk)
A global mobile virtual network operator offering low-cost international calls, data, and minutes to 23 countries with a digital-first approach | Telecommunications | π¬π§ London | 1,369 | 2006 |
| 17 | [Hyperoptic](https://www.tamtam.ai/c/hyperoptic) (hyperoptic.com)
The company provides ultra-reliable full-fibre broadband with top speeds, no mid-contract price hikes, and exceptional customer service | Telecommunications | π¬π§ London | 1,358 | 2010 |
| 18 | [Boldyn Networks](https://www.tamtam.ai/c/boldyn-networks) (mobilitie.com)
A US-based telecommunications infrastructure company providing wireless solutions for robust coverage and 5G services at large venues and cities | Telecommunications | π¬π§ London | 1,286 | 2005 |
| 19 | [Maintel](https://www.tamtam.ai/c/maintel) (maintel.co.uk)
Provider of cloud communications and managed services, specializing in digital transformation for public and private sectors Delivering digital workplace, customer experience, and secure connectivity solutions globally | Telecommunications | π¬π§ London | 946 | 1991 |
| 20 | [Inmarsat](https://www.tamtam.ai/c/inmarsat) (viasat.com)
Account closed, follow Viasat company page for satellite communications news due to acquisition. No longer posting here. | Telecommunications | π¬π§ London | 939 | |
| 21 | [Helios Towers](https://www.tamtam.ai/c/helios-towers) (heliostowers.com)
Builds, owns, operates telecom passive infrastructure across Africa, enabling mobile operators to expand coverage and improve network access efficiently. | Telecommunications | π¬π§ London | 933 | 2009 |
| 22 | [EXA Infrastructure](https://www.tamtam.ai/c/exa-infrastructure) (exainfra.net)
A leading digital infrastructure platform in Europe and North America, owning a vast fibre network, data centers, and sub-sea routes for optimal connectivity | Telecommunications | π¬π§ London | 846 | 2021 |
| 23 | [Africell Group](https://www.tamtam.ai/c/africell-group) (africell.com)
A mobile technology company providing fast, low-cost, and reliable mobile network coverage and innovative services to over sixteen million subscribers in sub-Saharan Africa | Telecommunications | π¬π§ London | 845 | 2000 |
| 24 | [GCX](https://www.tamtam.ai/c/gcx) (gcxworld.com)
Network services enabling digital transformation through managed SD-WAN, hybrid networks, and extensive subsea cloud connectivity across emerging markets and Asia. | Telecommunications | π¬π§ London | 810 | 1988 |
| 25 | [Industria](https://www.tamtam.ai/c/industria) (industria.com)
A leading provider of broadband network and entertainment solutions, offering turn-key services to operators and achieving significant milestones in connectivity and innovation | Telecommunications | π¬π§ London | 788 | 2004 |
| 26 | [Lycatel](https://www.tamtam.ai/c/lycatel) (lycagroup.com)
The company is a global market leader in the calling card market and Europe's largest International MVNO Mobile brand, serving millions of customers worldwide | Telecommunications | π¬π§ London | 647 | 2002 |
| 27 | [MYCOM OSI](https://www.tamtam.ai/c/mycom-osi) (mycom-osi.com)
Provide network assurance and service experience solutions for CSPs and enterprises to manage 5G and enterprise services efficiently. | Telecommunications | π¬π§ London | 557 | 1997 |
| 28 | [Community Fibre Limited](https://www.tamtam.ai/c/community-fibre-limited) (communityfibre.co.uk)
Provider of Londonβs fastest, most reliable, and sustainable full fibre broadband network with excellent customer service and value. | Telecommunications | π¬π§ London | 540 | 2013 |
| 29 | [euNetworks](https://www.tamtam.ai/c/eunetworks) (eunetworks.com)
A European provider of bandwidth infrastructure services, offering scalable fibre-based products for data center connectivity and cloud services across 17 countries in Europe | Telecommunications | π¬π§ London | 417 | 2002 |
| 30 | [Monty Mobile](https://www.tamtam.ai/c/monty-mobile) (montymobile.com)
Partnering with operators, enterprises, hyperscalers, and financial institutions to strengthen connectivity, advance technologies, and accelerate digital transformation worldwide with integrated solutions across various domains. | Telecommunications | π¬π§ London | 408 | 1998 |
## How this list is built
Every company on this list has a Tamtam company profile. The industry is the one the company gives on LinkedIn; categories such as SaaS or fintech are classified by Tamtam's AI from the company's website and LinkedIn page; and the headquarters city must match the company's own address. Companies are ranked by the number of employees on LinkedIn, and the list is refreshed every night. Classifications can be wrong, so treat the list as a starting point rather than an official ranking. Last updated Nov 12, 2026.
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## The same list elsewhere in United Kingdom
- [Telecommunications companies in the United Kingdom](https://www.tamtam.ai/l/telecommunications-companies-united-kingdom) (216)
## The same list elsewhere
- [Telecommunications companies in the world](https://www.tamtam.ai/l/telecommunications-companies-in-the-world) (3,307)
- [Telecommunications companies in Europe](https://www.tamtam.ai/l/telecommunications-companies-in-europe) (1,294)
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Source: https://www.tamtam.ai/l/telecommunications-companies-london