Company lists · Data refreshed September 2026

Top 25 IT systems integration firms based in the United Kingdom

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

Compiled by the RevenueBase Data Team Data refreshed Sep 28, 2026 1,373 companies tracked

RevenueBase identified 1,373 IT systems integration firms headquartered in the United Kingdom as of September 2026 and tracks 18,383 professional contacts across them, including 7,303 with verified work emails. London is the largest hub.

This list covers IT systems integration firms headquartered in the 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

1,373Companies

18,383Contacts tracked

7,303Verified emails

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The 25 largest IT systems integration firms based in the United Kingdom

Ranked by team size

Top 25 of 1,373 IT systems integration firms based in the 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	Nasstar	Indirect evidence	Wakefield, United KingdomHQ checked Sep 28, 2026	1,001-5,000	844 contacts →
	Indirect evidence “Complexity isn’t the enemy.” Source: RevenueBase Database · checked Sep 28, 2026
2	XMA	Indirect evidence	Reading, United KingdomHQ checked Sep 28, 2026	501-1,000	538 contacts →
	Indirect evidence “Unlock your potential with XMA.” Source: RevenueBase Database · checked Sep 28, 2026
3	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
4	Trinity Fire & Security Systems	Indirect evidence	Exeter, United KingdomHQ checked Sep 28, 2026	501-1,000	386 contacts →
	Indirect evidence “Trinity’s mission statement is simple - to provide high quality design, installation, commissioning and long term after care of Fire Detection, Fire Suppression, Life Safety and…” Source: RevenueBase Database · checked Sep 28, 2026
5	Capula	Strong evidence	Stone, United KingdomHQ checked Sep 28, 2026	201-500	351 contacts →
	Strong evidence “What we do \| With a focus on operational technology and digital transformation, Capula has been a leader in advanced system integration for decades; optimising efficiency &…” Source: RevenueBase Database · checked Sep 28, 2026
6	Kings Secure Technologies	Partial evidence	Bradford, United KingdomHQ checked Sep 28, 2026	501-1,000	326 contacts →
	Partial evidence “Kings Secure Technologies (KST) is a high-end, enterprise-level systems integrator.” Source: RevenueBase Database · checked Sep 28, 2026
7	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
8	BOXXE	Partial evidence	Hemel Hempstead, United KingdomHQ checked Sep 28, 2026	201-500	295 contacts →
	Partial evidence “boxxe is a leading provider of hardware, software, and managed IT services for public and private sector organisations.” Source: RevenueBase Database · checked Sep 28, 2026
9	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
10	Aire Logic Limited	Indirect evidence	Leeds, United KingdomHQ checked Sep 28, 2026	201-500	255 contacts →
	Indirect evidence “Aire Logic is an ICT Strategy, software development and product development company with particular emphasis on the healthcare industry and particular experience in creating…” Source: RevenueBase Database · checked Sep 28, 2026
11	ITI Group	Indirect evidence	Sheffield, United KingdomHQ checked Sep 28, 2026	201-500	234 contacts →
	Indirect evidence “For organisations facing the compounding threats of ageing assets, a retiring workforce, and evolving cyber attacks, the status quo is no longer an option.” Source: RevenueBase Database · checked Sep 28, 2026
12	Evolution Electronic Security Systems LTD	Partial evidence	Marlow, United KingdomHQ checked Sep 28, 2026	201-500	200 contacts →
	Partial evidence “Founded in 1996 we have grown into one of the UK and Ireland’s leading qualified and accredited security and fire systems integrators, working across Europe to bring together…” Source: RevenueBase Database · checked Sep 28, 2026
13	ITPS	Indirect evidence	Chester Le Street, United KingdomHQ checked Sep 28, 2026	51-200	197 contacts →
	Indirect evidence “Our team has decades of experience in delivering complex, challenging projects that help clients across the private, public and not-for-profit sectors do business better.” Source: RevenueBase Database · checked Sep 28, 2026
14	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
15	Platned	Indirect evidence	Gerrards Cross, United KingdomHQ checked Sep 28, 2026	201-500	190 contacts →
	Indirect evidence “Platned helps organisations simplify complex change and get more value from their enterprise technology investments.” Source: RevenueBase Database · checked Sep 28, 2026
16	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
17	Vohkus	Partial evidence	Fareham, United KingdomHQ checked Sep 28, 2026	51-200	184 contacts →
	Partial evidence “Vohkus is a rapidly growing, highly agile UK IT supplier specialising in end-to-end IT supply, enterprise infrastructure solutions, and comprehensive managed services.” Source: RevenueBase Database · checked Sep 28, 2026
18	Barron Mccann Limited	Partial evidence	Derby, United KingdomHQ checked Sep 28, 2026	201-500	170 contacts →
	Partial evidence “Barron McCann install, deploy and maintain IT technology for some of the world’s largest brands in the retail, hospitality, leisure and corporate sectors.” Source: RevenueBase Database · checked Sep 28, 2026
19	DOWDS	Strong evidence	Ballymena, United KingdomHQ checked Sep 28, 2026	201-500	164 contacts →
	Strong evidence “With 45+ years in business, Dowds expertise spans the full lifecycle of complex build environments – from initial design and systems integration to final handover and beyond.” Source: RevenueBase Database · checked Sep 28, 2026
20	Charterhouse Group	Indirect evidence	Aldgate, United KingdomHQ checked Sep 28, 2026	51-200	163 contacts →
	Indirect evidence “Connecting You Across the UK and Worldwide Our team of accredited engineers and consultants cover a broad range of technologies, enabling us to deliver innovative solutions.” Source: RevenueBase Database · checked Sep 28, 2026
21	WTL LTD	Partial evidence	Birmingham, United KingdomHQ checked Sep 28, 2026	n/a	162 contacts →
	Partial evidence “For over 35 years now WTL has been providing seamlessly integrated IT solutions and managed services to medium and large enterprises within the UK, including major clients within…” Source: RevenueBase Database · checked Sep 28, 2026
22	Portal	Indirect evidence	Bracknell, United KingdomHQ checked Sep 28, 2026	51-200	141 contacts →
	Indirect evidence Source: RevenueBase Database · checked Sep 28, 2026
23	Sisl Global	Strong evidence	Uxbridge, United KingdomHQ checked Sep 28, 2026	1,001-5,000	128 contacts →
	Strong evidence “SISL Infotech is a market-leading IT infrastructure reseller and systems integrator with operations in EMEA / NAM / LATAM / APAC - data centre & cloud solutions - network…” Source: RevenueBase Database · checked Sep 28, 2026
24	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
25	CINOS	Partial evidence	Frimley, United KingdomHQ checked Sep 28, 2026	51-200	119 contacts →
	Partial evidence “Cinos is an industry-leading, agile, and innovative systems integrator.” 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 25 of 1,373 IT systems integration firms based in the United Kingdom

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IT systems integration firms based in the United Kingdom at a glance

As of Sep 28, 2026

39.7%Verified-email coverage

13.4Average contacts per company

1-10Median size (employees)

27.1%Largest-city concentration · London

Sep 28, 2026Page data refreshed

Companies by employee count

1-10

772

11-50

419

51-200

135

201-500

501-1,000

1,001-5,000

5,001-10,000

10001+

Email recency for this list is measured worldwide rather than for United Kingdom, so it is reported there. Company counts and contact totals on this page are exact for United Kingdom, over 1,373 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 the 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 United Kingdom 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, 7,303 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

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 the United Kingdom?

RevenueBase identified 1,373 IT systems integration firms headquartered in the 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?

Nasstar, headquartered in Wakefield, tops this list with the largest team on record.

Which city has the most IT systems integration firms?

London leads 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 7,303 verified decision-maker contacts tracked across these 1,373 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.