Company lists · Data refreshed September 2026

Top 24 IT systems integration firms based in London, United Kingdom

Name: IT systems integration firms based in London, United Kingdom
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 28, 2026 372 companies tracked

RevenueBase identified 372 IT systems integration firms headquartered in London, United Kingdom as of September 2026 and tracks 5,087 professional contacts across them, including 1,566 with verified work emails. Across the United Kingdom, London is the largest hub for this category.

This list covers IT systems integration firms headquartered in London, United Kingdom, matched on what each company actually does as described in its own words. Ranked by team size, largest first. Every row shows the company's own description, its RevenueBase Smart Search rating, and when it was last checked. Data refreshed September 28, 2026.

Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase Smart Search, the natural-language company search RevenueBase customers use to build their own targeted lists and unlock verified emails and direct dials at the companies on them. How these lists are built and judged.

How to read this list HQ checked on every row RevenueBase Smart Search rating on every row Refreshed Sep 28, 2026 86% judged on-target in blind review

372Companies

5,087Contacts tracked

1,566Verified emails

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The 24 largest IT systems integration firms based in London, United Kingdom

Ranked by team size

Top 24 of 372 IT systems integration firms based in London, United Kingdom, ranked by team size, largest first. Data refreshed Sep 28, 2026. RevenueBase Smart Search rates how each company's information relates to IT systems integration firms: strong evidence (its own description names it), partial (names part of it), indirect (matched on the rest of its profile rather than the description shown). Click a contact count to view that company's people.
#	Company	RevenueBase Smart Search	Headquarters	Employees	Contacts
1	Zenzero	Partial evidence	London, United KingdomHQ checked Sep 28, 2026	501-1,000	401 contacts →
	Partial evidence “We believe successful businesses are underpinned by quality IT infrastructure.” Source: RevenueBase Database · checked Sep 28, 2026
2	ARCH	Indirect evidence	London, United KingdomHQ checked Sep 28, 2026	n/a	307 contacts →
	Indirect evidence “Arch has specialised in SAP solutions for over 25 years and our team has extensive experience of SAP technologies and SAP usability.” Source: RevenueBase Database · checked Sep 28, 2026
3	OLR	Partial evidence	London, United KingdomHQ checked Sep 28, 2026	201-500	292 contacts →
	Partial evidence “OLR is a specialist Oracle Retail systems integrator delivering end-to-end omnichannel solutions to enable leading retailers to accelerate business success through system…” Source: RevenueBase Database · checked Sep 28, 2026
4	Eappsys	Partial evidence	London, United KingdomHQ checked Sep 28, 2026	51-200	193 contacts →
	Partial evidence “eAppSys is a systems integrator that is focused exclusively on supporting the core enterprise application systems within Oracle On-Premise and Cloud Applications.” Source: RevenueBase Database · checked Sep 28, 2026
5	Maintel Azzurri Communications	Partial evidence	London, United KingdomHQ checked Sep 28, 2026	501-1,000	186 contacts →
	Partial evidence “Maintel is a leading systems integrator and managed services provider, delivering effortless communications solutions to a broad spectrum of businesses in the UK and…” Source: RevenueBase Database · checked Sep 28, 2026
6	Opticoreit	Partial evidence	London, United KingdomHQ checked Sep 28, 2026	51-200	120 contacts →
	Partial evidence “OpticoreIT is an IT Consultancy founded in 2013 to bridge a gap in the market between the major IT services providers and the consultancy market.” Source: RevenueBase Database · checked Sep 28, 2026
7	Nephos Technologies	Partial evidence	London, United KingdomHQ checked Sep 28, 2026	51-200	80 contacts →
	Partial evidence “Nephos Technologies is an independent data systems integrator, specialising in helping organisations transform the way they store, manage and protect their data.” Source: RevenueBase Database · checked Sep 28, 2026
8	Advisority	Partial evidence	London, United KingdomHQ checked Sep 28, 2026	51-200	61 contacts →
	Partial evidence “We are the trusted IT integrator that specialises in making your work flow.” Source: RevenueBase Database · checked Sep 28, 2026
9	FMK	Partial evidence	London, United KingdomHQ checked Sep 28, 2026	n/a	59 contacts →
	Partial evidence “A full service consultancy company specialising integrating Macintosh and Windows.” Source: RevenueBase Database · checked Sep 28, 2026
10	Diegesis Limited	Strong evidence	London, United KingdomHQ checked Sep 28, 2026	51-200	52 contacts →
	Strong evidence “Diegesis is a business technology and IT systems integration company that specialises in Decision Support Solutions.” Source: RevenueBase Database · checked Sep 28, 2026
11	Pace Integration	Strong evidence	London, United KingdomHQ checked Sep 28, 2026	51-200	47 contacts →
	Strong evidence “Pace Integration is a unique technology consultancy that solves your integration challenge – focused on enterprise systems integration strategy, architecture and design that is…” Source: RevenueBase Database · checked Sep 28, 2026
12	Influential Software	Partial evidence	London, United KingdomHQ checked Sep 28, 2026	51-200	42 contacts →
	Partial evidence “Influential is a boutique systems integrator, and fully certified partner with Microsoft, IBM Cognos, SAP Business Objects, Boomi and Vena, offering licence sales, support…” Source: RevenueBase Database · checked Sep 28, 2026
13	Forge Technologies	Partial evidence	London, United KingdomHQ checked Sep 28, 2026	51-200	41 contacts →
	Partial evidence “Forge Technologies is a digital IT services business focusing on four technology pillars; Digital App & Innovation, Future Workplace, Cloud Optimisation and Network Transformation.” Source: RevenueBase Database · checked Sep 28, 2026
14	Phoenix47	Partial evidence	London, United KingdomHQ checked Sep 28, 2026	51-200	40 contacts →
	Partial evidence “Phoenix47 is an IT infrastructure services company providing Support Desk, Managed Services and Professional Services.” Source: RevenueBase Database · checked Sep 28, 2026
15	Link Media Systems	Partial evidence	London, United KingdomHQ checked Sep 28, 2026	51-200	37 contacts →
	Partial evidence “We are systems integrators.” Source: RevenueBase Database · checked Sep 28, 2026
16	R3 Digital	Partial evidence	London, United KingdomHQ checked Sep 28, 2026	11-50	37 contacts →
	Partial evidence “R3 Digital is a Systems Integrator and Salesforce Platinum (Summit) Consulting Partner that specialises in Health and Life Sciences.” Source: RevenueBase Database · checked Sep 28, 2026
17	3li Global	Indirect evidence	London, United KingdomHQ checked Sep 28, 2026	51-200	36 contacts →
	Indirect evidence “Most businesses don't have a CRM problem.” Source: RevenueBase Database · checked Sep 28, 2026
18	MIX Consultancy LTD	Partial evidence	London, United KingdomHQ checked Sep 28, 2026	11-50	32 contacts →
	Partial evidence “MiX is an independent consultancy specialising in IT Infrastructure, Communication, Data Centre, Audio Visual, Physical Security & SMART Buildings Technology Solutions.” Source: RevenueBase Database · checked Sep 28, 2026
19	Cloudcoco PLC	Partial evidence	London, United KingdomHQ checked Sep 28, 2026	11-50	32 contacts →
	Partial evidence “CloudCoCo helps organisations modernise, secure and scale their IT with services designed for the way businesses work now.” Source: RevenueBase Database · checked Sep 28, 2026
20	Okto Technologies	Partial evidence	London, United KingdomHQ checked Sep 28, 2026	11-50	32 contacts →
	Partial evidence “Master Systems Integrator OKTO Technologies is a leader in the design, development & installation of Smart Building Technology for- SuperPrime Residential - Luxury Hospitality -…” Source: RevenueBase Database · checked Sep 28, 2026
21	DD Consulting	Partial evidence	London, United KingdomHQ checked Sep 28, 2026	n/a	32 contacts →
	Partial evidence “DD Consulting is a boutique consulting house specialising in M&A, integration and separation, taking all those skills into day-to-day business operations.” Source: RevenueBase Database · checked Sep 28, 2026
22	Maple Networks	Partial evidence	London, United KingdomHQ checked Sep 28, 2026	11-50	30 contacts →
	Partial evidence “We’re the team that the IT leaders of tech-dependant organisations come to when they need to really shake things up, innovate (effectively), and tackle their transformational…” Source: RevenueBase Database · checked Sep 28, 2026
23	Manifest Software Solutions	Indirect evidence	London, United KingdomHQ checked Sep 28, 2026	11-50	28 contacts →
	Indirect evidence “Manifest Software Solutions (MSS) integrates anything with everything.” Source: RevenueBase Database · checked Sep 28, 2026
24	Torpedo Factory Group	Partial evidence	London, United KingdomHQ checked Sep 28, 2026	51-200	27 contacts →
	Partial evidence “AMAZING DIGITAL EXPERIENCES THAT WOW BY DESIGN Torpedo Factory Group is a Master Systems Integrator providing professional services for Intelligent Environments & Smart Buildings…” Source: RevenueBase Database · checked Sep 28, 2026

RevenueBase Smart Search

RevenueBase Smart Search assesses information from a company’s LinkedIn profile, information supplied directly by the company, its website, and other publicly available sources. It uses that information to rate how closely the company relates to this list’s category: IT systems integration firms. Every row carries its rating and the description the rating was read from, so each one can be checked rather than taken on trust.

Strong evidence: The company's own public description of its business names IT systems integration firms.
Partial evidence: Its own public description names part of IT systems integration firms, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name IT systems integration firms. The match rests on the rest of the company's public profile rather than the one sentence quoted here, so this is the rating to check first.

RevenueBase Smart Search is how these lists are built: RevenueBase's data engine and AI assemble the companies that match a category defined in a user's own words, so a list can be about what companies actually do rather than about whichever industry code they were filed under.

Showing 24 of 372 IT systems integration firms based in London, United Kingdom

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IT systems integration firms based in London, United Kingdom at a glance

As of Sep 28, 2026

30.8%Verified-email coverage

13.7Average contacts per company

11-50Median size (employees)

Sep 28, 2026Page data refreshed

Companies by employee count

1-10

185

11-50

121

51-200

201-500

501-1,000

1,001-5,000

5,001-10,000

10001+

Email recency for this list is measured across the whole United Kingdom list rather than for London, so it is reported there. Company counts and contact totals on this page are exact for London, over 372 companies.

How this list was built

Company categories are rarely black and white. RevenueBase reads each company's own description of its business to decide whether it belongs among IT systems integration firms, so some rows will be adjacent to the category rather than pure plays. The description and RevenueBase Smart Search rating on every row are there so you can check each match yourself.

Source: The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase Smart Search, the natural-language company search available to every RevenueBase user.
What qualifies: Companies headquartered in London, United Kingdom whose own description of what they do matches “IT systems integration firms”. Matching reads each company's description, not its industry code or its name.
RevenueBase Smart Search: RevenueBase Smart Search is how this list is assembled and how each row is rated. RevenueBase's data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to a category defined in a user's own words. Each row is rated strong evidence (its own description names IT systems integration firms), partial evidence (it names part of the category) or indirect evidence (the description shown names none of it and the match rests on the rest of the company's profile). The description supporting each rating is quoted on the row.
What we exclude: Companies whose own description does not clearly place them among IT systems integration firms, and records with no verified work email. Companies headquartered outside London are excluded even when they keep an office there.
Match quality: In blind human judging of this matching method, 86% of matched companies were on target. Expect roughly 1 in 7 rows to be adjacent to the category rather than a pure play. Every row shows the company's own description and its RevenueBase Smart Search rating so you can judge each match yourself. Read the full methodology: how the lists are built, how the judging worked, and what the figure means.
Ranking: Team size, largest first: companies are ordered by the number of professionals RevenueBase tracks at each one. Employee ranges shown are reported bands, for context.
Verification: Every listed company carries at least one verified work email, 1,566 across the full list. Contacts re-verify on a rolling cadence, and each contact's own verification date is shown inside RevenueBase.
Refresh: This page's figures were pulled from the company graph on September 28, 2026. Lists refresh periodically as the graph is re-checked.
Corrections: Wrong category, wrong headquarters, or a company that has closed? Use “Report an issue” on any row. Reports go to the RevenueBase Data Team and feed back into the company graph.

IT systems integration firms by metro in the United Kingdom

IT systems integration firms in Manchester26

Frequently asked

What is RevenueBase Smart Search?

RevenueBase Smart Search is how RevenueBase decides which companies belong on this list and how strongly each one fits. Its data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to the category the list is about. Each row is rated strong evidence when the company's own description names IT systems integration firms, partial evidence when it names part of the category, and indirect evidence when the description shown names none of it and the match rests on the rest of the company's profile.

How many IT systems integration firms are there based in London, United Kingdom?

RevenueBase identified 372 IT systems integration firms headquartered in London, United Kingdom as of September 2026, matched on each company's own description of what it does rather than its industry code.

What is the largest company on this list?

Zenzero, headquartered in London, tops this list with the largest team on record.

Which city in the United Kingdom has the most IT systems integration firms?

London leads the United Kingdom with 372 headquartered companies, followed by Manchester (26) and Bristol (21).

How do I get contact information for these companies?

A free RevenueBase account lets you run this exact search and work the top results, verified emails and direct dials included. Upgrading unlocks all 1,566 verified decision-maker contacts tracked across these 372 companies.

How current is this list?

The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on September 28, 2026.

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About this data

RevenueBase is a B2B data infrastructure company. Its company graph covers 60 million companies and 398.9 million professional contacts, with emails verified on a rolling cadence rather than scraped once and left to decay. These company lists are generated directly from that graph with RevenueBase Smart Search, the same natural-language company search every RevenueBase user has: describe a market in plain words, get the companies that match, and add verified emails and direct dials for the people at them. It is the same data that powers RevenueBase's B2B data products, and a free account includes 500 credits to start. How these lists are built and judged.