# The 30 largest managed service providers in London
Tamtam tracks 92 managed service providers headquartered in London. This list ranks the 30 largest by number of employees on LinkedIn, led by Vodafone Business, Colt Technology Services and Infobip. Their median headcount is 782. Half of them were founded in 2004 or later.
This list contains large to mid-sized managed service providers based in London, primarily in IT services and telecommunications. Key players include Vodafone Business, offering mobile, fixed, unified communications, and IoT services, and Colt Technology Services, a global digital infrastructure provider. Other notable companies are Infobip, specializing in omnichannel engagement, and Claranet, a technology services provider in Cloud, Networks, Cyber Security, and Workplace technologies. Gamma supplies Unified Communications services.
The data shows a concentration of companies founded between the mid-1990s and early 2000s, such as Colt Technology Services (1992), Claranet (1996), and Gamma (2002). Several companies also focus on global service delivery, like NSC Global, which provides IT services to clients in over 180 countries, and NTT Global Data Centers, offering reliable data centers worldwide.
π¬π§ London Β· 30 companies Β· Updated Nov 12, 2026
| # | Company | Industry | Headquarters | Employees | Founded |
|---|---|---|---|---|---|
| 1 | [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 | |
| 2 | [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 |
| 3 | [Infobip](https://www.tamtam.ai/c/infobip) (infobip.com)
Global leader in omnichannel engagement, providing messaging tools and solutions for customer engagement, authentication, and security with a strong focus on quality engineering | IT Services and IT Consulting | π¬π§ London | 3,501 | 2006 |
| 4 | [Claranet](https://www.tamtam.ai/c/claranet) (claranet.com)
A global technology services provider offering managed services, professional services, and training in Cloud, Networks, Cyber Security, and Workplace technologies since 1996 | IT Services and IT Consulting | π¬π§ London | 3,073 | 1996 |
| 5 | [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 |
| 6 | [NTT Global Data Centers](https://www.tamtam.ai/c/ntt-global-data-centers) (services.global.ntt)
Global Data Centers, now a part of NTT DATA, offers neutral access to cloud providers, internet exchanges, and telecom providers with reliable data centers worldwide | IT Services and IT Consulting | π¬π§ London | 2,449 | |
| 7 | [Canonical](https://www.tamtam.ai/c/canonical) (canonical.com)
Publishing Ubuntu, popular enterprise Linux, open source delivery, cloud to edge, secure, cost-effective, global community, developer platform, remote-first company. | Software Development | π¬π§ London | 2,001 | 2004 |
| 8 | [CSC UKI](https://www.tamtam.ai/c/csc-uki) (dxc.com)
A leading independent IT services company formed through the merger of HPE Enterprise Services and CSC, offering end-to-end solutions with longevity | Outsourcing and Offshoring Consulting | π¬π§ London | 1,442 | |
| 9 | [Connect](https://www.tamtam.ai/c/connect-london) (weconnect.tech)
Communication experts providing solutions in Contact Centre, Unified Communications, and Network Services, delivering digital transformation through bespoke strategies for businesses globally | IT Services and IT Consulting | π¬π§ London | 1,387 | 1990 |
| 10 | [Advania UK](https://www.tamtam.ai/c/advania-uk) (advania.co.uk)
Specializes in Microsoft technologies like AI, Azure, and Dynamics 365 to deliver transformational IT services and sustainable value for customers. | IT Services and IT Consulting | π¬π§ London | 1,351 | |
| 11 | [NSC Global](https://www.tamtam.ai/c/nsc-global) (nscglobal.com)
This company simplifies global business with expert teams delivering IT services to clients in over 180 countries, flexibly adapting to their needs | IT Services and IT Consulting | π¬π§ London | 1,070 | 1997 |
| 12 | [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 |
| 13 | [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 |
| 14 | [Cobra](https://www.tamtam.ai/c/cobra) (amazingsupport.co.uk)
We successfully completed a company acquisition in June 2012 resulting in a re-brand to Amazing Support, providing quality business solutions | IT Services and IT Consulting | π¬π§ London | 831 | 2007 |
| 15 | [Kerv](https://www.tamtam.ai/c/kerv) (kerv.com)
Kerv is a purpose-driven cloud and digital services organization providing enterprise software, consulting, networking, security, and digital transformation services across key industries | IT Services and IT Consulting | π¬π§ London | 782 | 2020 |
| 16 | [Beyond](https://www.tamtam.ai/c/beyond) (bynd.com)
A design agency focused on enhancing customer experiences through strategy, technology, and design, serving diverse clients globally with a remote-first workforce | IT Services and IT Consulting | π¬π§ London | 752 | 2010 |
| 17 | [UBIO](https://www.tamtam.ai/c/ubio) (ub.io)
UBIO connects websites and APIs to collect data for clients like Google and trivago, enabling them to sell tickets and collect information | Technology, Information and Internet | π¬π§ London | 706 | 2013 |
| 18 | [Exponential-e](https://www.tamtam.ai/c/exponential-e) (exponential-e.com)
Provides superfast network and cloud infrastructure delivering tailored enterprise solutions including data centre, cloud, unified communications, security, and IT services. | IT Services and IT Consulting | π¬π§ London | 695 | 2002 |
| 19 | [Zenzero](https://www.tamtam.ai/c/zenzero) (zenzero.co.uk)
Design tailored IT infrastructure solutions using proven technologies to optimize client operations and maximize value from resources. | IT Services and IT Consulting | π¬π§ London | 688 | 2004 |
| 20 | [DSP](https://www.tamtam.ai/c/dsp-london) (dsp.co.uk)
Specializes in secure, optimized database management and consulting for Oracle, SQL Server, and multi-cloud environments including Azure and Oracle Cloud. | IT Services and IT Consulting | π¬π§ London | 679 | 1999 |
| 21 | [Onnec](https://www.tamtam.ai/c/onnec) (onnecgroup.com)
A leading technology partner offering end-to-end connectivity solutions including structured cabling, networking, managed services, and integrated intelligent systems for businesses globally | IT Services and IT Consulting | π¬π§ London | 665 | |
| 22 | [Options Technology](https://www.tamtam.ai/c/options-technology) (options-it.com)
Provides global financial technology solutions specializing in banking and trading infrastructure, integrating high-performance networking, cloud, security, and AI technologies. | IT Services and IT Consulting | π¬π§ London | 641 | 1993 |
| 23 | [Giacom](https://www.tamtam.ai/c/giacom) (giacom.com)
The company provides a platform for technology resellers and MSPs to access various services and products to create solutions for UK small businesses | IT Services and IT Consulting | π¬π§ London | 633 | |
| 24 | [Nscale](https://www.tamtam.ai/c/nscale) (nscale.com)
Specializing in AI, Nscale provides a GPU cloud platform in Europe for high-performance computing optimized for training and intensive workloads | Technology, Information and Internet | π¬π§ London | 585 | 2024 |
| 25 | [TelefΓ³nica Tech (EN)](https://www.tamtam.ai/c/telefonica-tech-en) (telefonicatech.uk)
Specialist provider of integrated technology solutions including cybersecurity, cloud, data, AI, business applications, and digital workplace services. | IT Services and IT Consulting | π¬π§ London | 557 | |
| 26 | [Fortray Global Service Limited](https://www.tamtam.ai/c/fortray-global-service-limited) (fortray.com)
Provides services for digital transformation, cybersecurity, cloud, and managed IT. Also develops talent through tech and AI bootcamps for various digital skills. | IT Services and IT Consulting | π¬π§ London | 547 | 2011 |
| 27 | [Colt Data Centre Services](https://www.tamtam.ai/c/colt-data-centre-services) (coltdatacentres.net)
Specializing in data centre services, the company designs, builds, manages, and innovates infrastructure solutions to support customers' growth globally | IT Services and IT Consulting | π¬π§ London | 483 | |
| 28 | [Hitachi Solutions UK](https://www.tamtam.ai/c/hitachi-solutions-uk) (hitachi-solutions.co.uk)
Provides business-tailored services and solutions for transformation journeys, including finance, low code, AI, and data-based transformation, offering advisory and application support. | IT Services and IT Consulting | π¬π§ London | 462 | 2012 |
| 29 | [Global Switch](https://www.tamtam.ai/c/global-switch) (globalswitch.com)
Ownership and operation of large-scale, carrier-neutral data centers across Europe and Asia-Pacific, providing secure, resilient solutions to diverse customers. | Real Estate | π¬π§ London | 447 | 1998 |
| 30 | [Easynet Group](https://www.tamtam.ai/c/easynet-group) (easynet.com)
A provider of managed services for national and global businesses, offering network, hosting, and unified communications solutions, along with security and application performance management | Telecommunications | π¬π§ London | 408 | 1994 |
## 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.
## More company lists in London
- [The largest companies in London](https://www.tamtam.ai/l/largest-companies-london) (12,882)
- [Multinational companies in London](https://www.tamtam.ai/l/multinational-companies-london) (3,652)
- [Financial Services companies in London](https://www.tamtam.ai/l/financial-services-companies-london) (1,862)
- [Financial services firms in London](https://www.tamtam.ai/l/financial-services-firms-london) (1,824)
- [SaaS companies in London](https://www.tamtam.ai/l/saas-companies-london) (1,615)
- [Professional services firms in London](https://www.tamtam.ai/l/professional-services-firms-london) (1,248)
- [Software Development companies in London](https://www.tamtam.ai/l/software-development-companies-london) (1,217)
- [Retail chains in London](https://www.tamtam.ai/l/retail-chains-london) (942)
- [IT Services and IT Consulting companies in London](https://www.tamtam.ai/l/it-services-and-it-consulting-companies-london) (693)
- [Companies with a mobile app in London](https://www.tamtam.ai/l/companies-with-mobile-app-london) (667)
- [Consulting firms in London](https://www.tamtam.ai/l/consulting-firms-london) (648)
- [IT services companies in London](https://www.tamtam.ai/l/it-services-companies-london) (607)
- [Subscription businesses in London](https://www.tamtam.ai/l/subscription-businesses-london) (544)
- [Venture capital and private equity firms in London](https://www.tamtam.ai/l/vc-and-private-equity-firms-london) (539)
- [Marketing and communications agencies in London](https://www.tamtam.ai/l/marketing-agencies-london) (533)
- [Retail Apparel and Fashion companies in London](https://www.tamtam.ai/l/retail-apparel-and-fashion-companies-london) (498)
- [Advertising Services companies in London](https://www.tamtam.ai/l/advertising-services-companies-london) (480)
- [Companies with in-house R&D in London](https://www.tamtam.ai/l/r-and-d-companies-london) (477)
- [AI companies in London](https://www.tamtam.ai/l/ai-companies-london) (456)
- [Investment Management companies in London](https://www.tamtam.ai/l/investment-management-companies-london) (452)
- [Hotel and hospitality groups in London](https://www.tamtam.ai/l/hospitality-groups-london) (445)
- [Luxury brands in London](https://www.tamtam.ai/l/luxury-brands-london) (428)
- [AI-native companies in London](https://www.tamtam.ai/l/ai-native-companies-london) (407)
- [E-commerce companies in London](https://www.tamtam.ai/l/ecommerce-companies-london) (384)
## The same list elsewhere in United Kingdom
- [Managed service providers in the United Kingdom](https://www.tamtam.ai/l/managed-service-providers-united-kingdom) (275)
## The same list elsewhere
- [Managed service providers in the world](https://www.tamtam.ai/l/managed-service-providers-in-the-world) (3,468)
- [Managed service providers in Europe](https://www.tamtam.ai/l/managed-service-providers-in-europe) (1,750)
---
Source: https://www.tamtam.ai/l/managed-service-providers-london