Top Managed IT Service Providers In London For 2027

London has hundreds of companies offering IT support, from one-person outfits to national groups with large service desks. For a business choosing a managed service provider (MSP), that choice is both an advantage and a problem. Most providers describe the same things on their websites: fixed monthly fees, 24/7 support, Microsoft 365, cyber security. The real differences are in sector experience, the size and depth of the service desk, security certifications, and whether an engineer can actually get to your office when something breaks.

To compare managed IT service providers in London we checked each provider against its own website. Every company below shows a London office address on its site, offers managed IT as a core service rather than a sideline, and publishes details we could verify, such as named clients, founding dates or certifications. Where a provider displays Cyber Essentials, Cyber Essentials Plus or ISO 27001 on its own site, we have noted it. We have mixed established mid-market providers with strong London independents and ordered them by our own judgement of strength and fit. No company paid to appear. For other suppliers in the capital, see our London services hub.

Certifications matter more than they used to. Cyber Essentials Plus is now a requirement for many public sector contracts and supply chains, and ISO 27001 is often expected by financial services and legal clients. A provider that holds these itself is better placed to help you achieve them.

London Managed IT Service Providers At A Glance

Provider	London Base	Best For	Core Services
Doherty Associates	Holborn, WC1V	Financial and legal firms	24/7 service desk, security, Microsoft 365, Azure
Transputec	Wembley, HA0	Mid-market organisations needing scale	Service desk, infrastructure, networks, cyber
Intersys	City of London, EC3V	Insurance and regulated financial services	Fixed-fee managed IT, cyber security, consulting
Wanstor	Borough, SE1	Multi-site mid-market organisations	Managed service desk, cloud, security, AI
Fifosys	West Hampstead, NW6	Growing businesses wanting full IT outsourcing	Fully managed IT, cloud, security, projects
ITVET	Soho, W1B	Property and real estate firms	Managed IT, cloud, cyber, connectivity
Fitzrovia IT	Fitzrovia, W1T	Security-conscious SMEs	IT support, Microsoft 365, managed security
Air IT	Clerkenwell, EC1M	SMEs wanting national backing	Managed and co-managed IT, cyber, cloud
Speedster IT	Whitechapel, E1	Small and medium London businesses	Fully managed IT, monitoring, helpdesk
Network Fish	Fitzrovia, W1W	SMEs with 5 to 250 users	Per-user managed IT, on-site engineers

Best Managed IT Service Provider Options In London

1. Doherty Associates — ISO 27001 Certified MSP Established In 1991

Doherty Associates was established in 1991 by Terry Doherty and is based on the 4th floor of The Connection, 198 High Holborn (WC1V 7BD). It employs well over 100 people, around 85% of them in technical roles, and runs its own in-house service desk rather than outsourcing first-line support.

Its managed service covers 24/7 support, cyber security, Microsoft 365, Copilot and AI, Azure, and application development and maintenance, with co-managed options for backup and disaster recovery, identity threat detection and patch management. The firm holds ISO 27001 and ISO 9001 and four Microsoft Solutions Partner designations. Testimonials on its site come from investment firms including Phoenix Equity Partners, Primary Capital and Westwind Capital.

Doherty is a strong choice for financial and legal services firms that want a long-established provider with certified security processes and a deep Microsoft bench.

2. Transputec — Privately Held MSP With 120+ Specialists

Transputec has its UK headquarters at Transputec House, 19 Heather Park Drive, Wembley (HA0 1SS). It says it has been trading for more than 40 years, remains privately held, and employs over 120 specialists across cyber, cloud and AI. Its pitch is a single accountable team covering service desk, infrastructure and networks with 24/7 cover.

The company lists ISO 27001, ISO 14001, ISO 9001 and Cyber Essentials Plus, plus Data Protection registration. It reports more than 1,000 projects delivered and names clients including Incisive Media, the Woodland Trust, Amber Infrastructure Group, Royal BAM Group, Corinthia Hotels and World Rugby.

Transputec suits mid-market and larger organisations that want a provider big enough to handle complex infrastructure, with a full set of security and quality certifications.

3. Intersys — Financial Services IT Specialist Founded In 1996

Intersys was founded in 1996 and has a City of London office at Leadenhall Market (EC3V 1LR), with its head office in Woodford Green. It has around 50 staff in IT support and services and more than 145 live clients, ranging from FTSE 100 organisations to SMEs.

Its sector focus is clear: financial services, insurance and reinsurance, fintech and wealth management. The managed service is offered for a fixed monthly fee, with unlimited phone and remote support and a dedicated engineer, alongside cyber security, IT consulting and cloud transformation. Intersys describes itself as “an ISO27001 certified, Cyber Essentials Plus provider”.

Intersys is a natural fit for Lloyd’s market firms, insurers and other regulated businesses in the City that want a provider used to their compliance requirements.

4. Wanstor — Award-Winning Service Desk For The Mid-Market

Wanstor is a managed IT provider at 124-126 Borough High Street (SE1 1LB) that focuses on UK mid-market organisations. It says it supports around 58,000 devices across 1,550 sites and handles about 13,500 tickets a month, which gives a sense of the scale of its service desk.

Its services span a 24/7 managed service desk, digital experience management, security, cloud foundations, and Microsoft AI adoption. Wanstor won MSP Service Desk of the Year and Best Service Desk CX at the SDI Awards 2024 to 2025. Clients named on its site include Catch22, The Arch Company, Look Ahead Care and Foresight.

Wanstor suits multi-site organisations, including charities, housing and care providers, that care about end-user experience as much as uptime.

5. Fifosys — ISO 27001 And Cyber Essentials Plus MSP Since 2001

Fifosys has supported UK businesses since 2001 from its office at Unit 6, 224 Iverson Road, West Hampstead (NW6 2HL). Its fully managed IT offer is described as a complete IT function covering user support, infrastructure, cyber security, cloud, projects, monitoring and strategic planning.

The company is ISO 27001 certified and holds Cyber Essentials Plus. Case studies on its site include Everyone Active, the leisure operator with more than 200 locations, a data centre migration for SHW, and a move to cloud-first IT for executive search firm Hedley May.

Fifosys fits growing businesses that want to hand over the whole IT function to a certified London provider, including strategy as well as day-to-day support.

6. ITVET — Managed IT Specialist For Commercial Property

ITVET has a London office at Linen Hall, Regent Street, Soho (W1B 5TB), with its head office in Bishop’s Stortford and a further office in Manchester. It has 19 years of experience supporting commercial and retail property and says it is trusted by more than 500 clients.

Its services include fully managed IT support, cloud, cyber security, WiFi, hardware, connectivity and communications. The site displays ISO 27001 and Cyber Essentials, along with ISO 22301, ISO 14001 and ISO 9001. Clients named include Savills, Legal & General, Aviva, CBRE, Hammerson, The Crown Estate, JLL and Knight Frank.

ITVET is the obvious specialist for property managers, landlords and real estate advisers, particularly those running building connectivity and tenant services as well as office IT.

7. Fitzrovia IT — Cyber Essentials Plus IT Support Since 1999

Fitzrovia IT has provided London IT support since 1999 from Holden House, 57 Rathbone Place (W1T 1JU). Its services include IT support, IT consultancy, Microsoft 365, cloud infrastructure, business continuity and office relocations, together with managed security, cyber security audits, penetration testing and cloud security.

The firm holds IASME Gold and Cyber Essentials Plus. Its site features a case study for accountancy network Ecovis and shows Drinkaware, Primesight and Vitabiotics among the businesses it supports.

Fitzrovia IT suits West End SMEs and professional firms that want a long-standing local provider with security work built into the managed service.

8. Air IT — National MSP With A Clerkenwell Office

Air IT is a national managed service provider focused on SMEs, with a London office at 75 Farringdon Road, Clerkenwell (EC1M 3JY). Its services cover managed IT support (including 24/7), cyber security, data and AI, cloud, modern workplace, and consultancy, offered as either fully managed or co-managed support.

The group lists Microsoft Solutions Partner and Apple Technical Partner status along with CREST membership, and offers Cyber Essentials services to clients. Its scale means London clients have access to a wider bench of engineers and specialists than a single-office provider can offer.

Air IT suits SMEs that want local London support backed by a larger national organisation, including firms with offices in other UK cities.

9. Speedster IT — London IT Support Partner Since 2004

Speedster IT has been a London IT support provider since 2004, based at 87 Whitechapel High Street (E1 7QX). Its fully managed IT service covers proactive monitoring, patching, security and helpdesk support, and the company says it has supported more than 500 businesses.

The firm is Cyber Essentials Plus certified and focuses on small and medium-sized London businesses that need dependable everyday support rather than complex enterprise infrastructure.

Speedster IT is a sensible option for East London and City SMEs looking for a proactive, certified provider with a long local track record.

10. Network Fish — Per-User Managed IT For London SMEs Since 2002

Network Fish (Fish Networks Limited) was founded in 2002 and is based on the 5th floor of 167-169 Great Portland Street, Fitzrovia (W1W 5PF). Its model is simple: “One number, one team, one monthly fee”, with a fixed price per user covering helpdesk support, on-site engineers, remote monitoring, security, Microsoft 365 and SaaS support, and endpoint backup.

The company holds Cyber Essentials and helps clients prepare for it. It typically works with businesses of 5 to 250 users in professional services, financial services, legal, creative and not-for-profit sectors.

Network Fish suits smaller London organisations that want predictable per-user pricing and an engineer who can be on site in central London.

How To Choose A Managed IT Service Provider In London

Which Certifications Should A London MSP Hold?

At a minimum, look for Cyber Essentials, and preferably Cyber Essentials Plus, which includes independent technical testing. If you work in financial services, legal or the public sector supply chain, ISO 27001 is a strong signal that the provider runs a formal information security management system. Ask to see current certificates and check their dates.

How Is Managed IT Usually Priced?

Most London providers charge a fixed monthly fee per user or per device, sometimes with a minimum contract value. Check what is included: on-site visits, out-of-hours cover, security tooling, backup and project work are often billed separately. Ask for a sample invoice from an existing client of similar size so you can see the real monthly cost.

What Service Levels Should You Expect?

Ask for response and resolution targets by priority level, and for recent performance reports against them. Clarify whether the service desk is in-house or outsourced, what hours it covers, and how quickly an engineer can reach your office. A provider with a central London base can usually get to a West End or City client far faster than one based outside the M25.

Do They Understand Your Sector?

Sector knowledge shapes everything from compliance to which line-of-business applications the provider can support. Insurers, property firms, law firms and charities each run specialist software and face different regulators. Ask for named references in your industry and speak to at least one of them.

How Easy Is It To Leave?

Check contract length, notice periods and exit terms before you sign. A good provider will document your environment, hand over admin credentials and support a transition if you move on. If those commitments are not in the contract, ask for them.

More London And UK Lists

• Top Cyber Security Companies In London For 2027
• Top Managed IT Service Providers In Manchester
• Top IT Support Companies For Small Business
• Top Software Development Companies In London
• Top AI Development Companies In London For 2027

Conclusion

London’s managed IT market rewards careful shortlisting. Larger organisations and regulated firms will find the depth they need at Doherty Associates, Transputec, Intersys and Wanstor, all of which run substantial service desks and publish their security credentials. Sector specialists such as ITVET for property and Intersys for insurance bring knowledge that generalists cannot match, while Fifosys, Fitzrovia IT, Speedster IT and Network Fish offer certified, local support for growing SMEs.

Shortlist two or three providers, ask each for references and a sample monthly invoice, and confirm certifications before you sign. For more vetted suppliers across the capital, visit the London services hub.