Company lists · Data refreshed September 2026

Top 25 Legacy system modernization firms based in London, United Kingdom

Name: Legacy system modernization 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 386 companies tracked

RevenueBase identified 386 company matches for legacy system modernization firms associated with London, United Kingdom as of September 2026 and tracks 15,526 professional contacts across them, including 8,388 with verified work emails. Across the United Kingdom, London is the largest hub for this category.

This list covers company matches for legacy system modernization firms associated with London, United Kingdom, found by RevenueBase SmartSearch using the meaning of business descriptions in its company graph at Exact. Ranked by professionals tracked, largest first. Rows show recorded descriptions where available, Exact search membership and the snapshot date. Data refreshed September 28, 2026.

Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase SmartSearch, 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 RevenueBase SmartSearch · Exact Recorded Sep 28, 2026 How this list was built

386Companies

15,526Contacts tracked

8,388Verified emails

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The 25 largest legacy system modernization firms based in London, United Kingdom

Ranked by team size

Top 25 of 386 company matches for legacy system modernization firms based in London, United Kingdom, ordered by professional contacts tracked in RevenueBase, largest first. Recorded Sep 28, 2026. The RevenueBase SmartSearch column shows Exact match membership in this saved search. Click a contact count to view that company's people. Totals use company locations recorded by RevenueBase; the displayed preview is a smaller selection.
#	Company	RevenueBase SmartSearch	Headquarters	Employees	Contacts
1	Endava	Exact match	London, United KingdomHQ recorded Sep 28, 2026	10001+	9,653 contacts →
	Exact match “For over two decades, we have been harnessing technology to drive meaningful change.” Recorded in the RevenueBase company graph · Sep 28, 2026 · View company records in RevenueBase
2	Acuvate	Exact match	London, United KingdomHQ recorded Sep 28, 2026	201-500	545 contacts →
	Exact match “At Acuvate, we empower enterprises to accelerate their Next gen transformation journeys with an AI-First approach.” Recorded in the RevenueBase company graph · Sep 28, 2026 · View company records in RevenueBase
3	Sandhata Technologies	Exact match	London, United KingdomHQ recorded Sep 28, 2026	201-500	363 contacts →
	Exact match “We are a global niche consultancy specialising in services that span all facets of Digital transformation, DevOps, and System Integration.” Recorded in the RevenueBase company graph · Sep 28, 2026 · View company records in RevenueBase
4	Devtech	Exact match	London, United KingdomHQ recorded Sep 28, 2026	201-500	266 contacts →
	Exact match “Devtech provides outcome-driven digital innovation services and helps companies better respond to change.” Recorded in the RevenueBase company graph · Sep 28, 2026 · View company records in RevenueBase
5	Cloudreach, An Eviden Business	Exact match	London, United KingdomHQ recorded Sep 28, 2026	501-1,000	261 contacts →
	Exact match “As of April 2023, Cloudreach is now part of Eviden, an atos business.” Recorded in the RevenueBase company graph · Sep 28, 2026 · View company records in RevenueBase
6	Parser	Exact match	London, United KingdomHQ recorded Sep 28, 2026	201-500	242 contacts →
	Exact match “At Parser we help organisations deliver impact through technology.” Recorded in the RevenueBase company graph · Sep 28, 2026 · View company records in RevenueBase
7	Flat Rock Technology	Exact match	London, United KingdomHQ recorded Sep 28, 2026	201-500	231 contacts →
	Exact match “Since 2008, Flat Rock Technology, a software engineering, SI, Cloud DevOps, Cyber Security, and Customer Experience (CX) company, has been at the forefront of providing innovative…” Recorded in the RevenueBase company graph · Sep 28, 2026 · View company records in RevenueBase
8	Tmotions Global Limited	Exact match	London, United KingdomHQ recorded Sep 28, 2026	201-500	228 contacts →
	Exact match “TMotions is inspired by forward-thinking businesses, who are now looking past recovery and shifting into the growth mode.” Recorded in the RevenueBase company graph · Sep 28, 2026 · View company records in RevenueBase
9	Daemon	Exact match	London, United KingdomHQ recorded Sep 28, 2026	51-200	145 contacts →
	Exact match “Founded in 2007, Daemon is a technology consultancy with a mission to make the world a better place by creating movements that power digital transformation.” Recorded in the RevenueBase company graph · Sep 28, 2026 · View company records in RevenueBase
10	Infosight Consulting	Exact match	London, United KingdomHQ recorded Sep 28, 2026	201-500	121 contacts →
	Exact match “At Infosight, we architect the future of enterprises by engineering your digital core and activating the intelligence within.” Recorded in the RevenueBase company graph · Sep 28, 2026 · View company records in RevenueBase
11	NEO Technology LTD	Exact match	London, United KingdomHQ recorded Sep 28, 2026	51-200	91 contacts →
	Exact match “Organisations are looking at what they need to do to enable growth and efficiency, we show you the ROI and drive the reason to change.” Recorded in the RevenueBase company graph · Sep 28, 2026 · View company records in RevenueBase
12	Constor Solutions	Exact match	London, United KingdomHQ recorded Sep 28, 2026	51-200	87 contacts →
	Exact match “At Constor Solutions, we believe that technology is the backbone of a successful business.” Recorded in the RevenueBase company graph · Sep 28, 2026 · View company records in RevenueBase
13	Intuition IT Intuitive Technology Recruitment	Exact match	London, United KingdomHQ recorded Sep 28, 2026	11-50	84 contacts →
	Exact match “IT'S NOT RECRUITMENT.” Recorded in the RevenueBase company graph · Sep 28, 2026 · View company records in RevenueBase
14	Integrella	Exact match	London, United KingdomHQ recorded Sep 28, 2026	51-200	82 contacts →
	Exact match “Integrella is a specialist IT services company with extensive experience across UK sectors.” Recorded in the RevenueBase company graph · Sep 28, 2026 · View company records in RevenueBase
15	Whizamet	Exact match	London, United KingdomHQ recorded Sep 28, 2026	51-200	65 contacts →
	Exact match “At Whizamet, we are a team of experienced professionals dedicated to empowering organizations to unlock the full potential of digital transformation.” Recorded in the RevenueBase company graph · Sep 28, 2026 · View company records in RevenueBase
16	31 Green	Exact match	London, United KingdomHQ recorded Sep 28, 2026	51-200	63 contacts →
	Exact match “At 31G, we know that developing a solution is just half the story.” Recorded in the RevenueBase company graph · Sep 28, 2026 · View company records in RevenueBase
17	200ok Solutions	Exact match	London, United KingdomHQ recorded Sep 28, 2026	11-50	59 contacts →
	Exact match “200OK Solutions is an architecture-led transformation firm, helping scaling organisations redesign their operational backbone through Intelligent Business Transformation (IBT).” Recorded in the RevenueBase company graph · Sep 28, 2026 · View company records in RevenueBase
18	Fusion Innovative	Exact match	London, United KingdomHQ recorded Sep 28, 2026	51-200	58 contacts →
	Exact match “One Stop Solution for all your Technological Needs for your Digital Success.” Recorded in the RevenueBase company graph · Sep 28, 2026 · View company records in RevenueBase
19	Albida	Exact match	London, United KingdomHQ recorded Sep 28, 2026	51-200	55 contacts →
	Exact match “Albida’s core focus is business transformation.” Recorded in the RevenueBase company graph · Sep 28, 2026 · View company records in RevenueBase
20	Cloudplexo	Exact match	London, United KingdomHQ recorded Sep 28, 2026	51-200	54 contacts →
	Exact match “CloudPlexo is a global technology consulting firm helping organizations transform, innovate, and build resilience through Cloud, AI, and Cybersecurity.” Recorded in the RevenueBase company graph · Sep 28, 2026 · View company records in RevenueBase
21	Definia	Exact match	London, United KingdomHQ recorded Sep 28, 2026	51-200	53 contacts →
	Exact match “We’re a technology and transformation consulting partner that helps organisations accelerate change with confidence.” Recorded in the RevenueBase company graph · Sep 28, 2026 · View company records in RevenueBase
22	Marionete	Exact match	London, United KingdomHQ recorded Sep 28, 2026	51-200	53 contacts →
	Exact match “Marionete is a technology consulting firm that empowers organizations to design innovative data strategies, drive digital transformation, and build advanced digital platforms.” Recorded in the RevenueBase company graph · Sep 28, 2026 · View company records in RevenueBase
23	Diegesis Limited	Exact match	London, United KingdomHQ recorded Sep 28, 2026	51-200	52 contacts →
	Exact match “Diegesis is a business technology and IT systems integration company that specialises in Decision Support Solutions.” Recorded in the RevenueBase company graph · Sep 28, 2026 · View company records in RevenueBase
24	Onepoint Consulting	Exact match	London, United KingdomHQ recorded Sep 28, 2026	51-200	52 contacts →
	Exact match “We build digital worlds with our collaborators to ensure all the worlds we live in reap the benefits.” Recorded in the RevenueBase company graph · Sep 28, 2026 · View company records in RevenueBase
25	Devbox	Exact match	London, United KingdomHQ recorded Sep 28, 2026	51-200	52 contacts →
	Exact match “Devbox Technologies is a UK based company that specializes in providing services related to the development, testing, maintenance, and enhancement of software applications for…” Recorded in the RevenueBase company graph · Sep 28, 2026 · View company records in RevenueBase

RevenueBase SmartSearch

Describe a niche business in your own words. RevenueBase SmartSearch compares the meaning of your description with company business descriptions compiled in the RevenueBase company graph. Exact, Similar, Related and Broad control how closely companies must fit.

This list uses Exact for “legacy system modernization firms”. Each Exact match badge shows membership in that saved search; it is not an individual similarity score or a service-quality rating. Recorded descriptions are shown where available.

Showing 25 of 386 legacy system modernization firms based in London, United Kingdom

See the full list, filter by size, metro and specialty, and access 8,388 tracked professional contacts with verified work emails. Direct dials are available where recorded.

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Legacy system modernization firms based in London, United Kingdom at a glance

As of Sep 28, 2026

54.0%Verified-email coverage

40.2Average contacts per company

11-50Median size (employees)

Sep 28, 2026Page data refreshed

Companies by employee count

1-10

188

11-50

127

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 386 companies.

How this list was built

The recorded descriptions help you assess these company matches. Check a company’s website for its current services and locations.

Source: The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase SmartSearch, the natural-language company search available to every RevenueBase user.
What qualifies: Company records associated with London, United Kingdom whose business descriptions match “legacy system modernization firms” by meaning at the Exact setting. Descriptions are compiled in the RevenueBase company graph from public websites, profiles and company information where available; they are not guaranteed quotations from the company's website.
RevenueBase SmartSearch: Describe a niche company in your own words to find businesses by meaning. Exact, Similar, Related and Broad control the breadth of RevenueBase SmartSearch. This saved list uses Exact. Each row's Exact match badge shows inclusion in that search, not an individual score or a service-quality judgment.
Public preview: The public preview omits records without a verified work email. Where headquarters information is recorded, preview rows are also filtered to this page’s location. Dataset totals and geographic summaries describe the full matched records before these preview filters.
Match quality: RevenueBase's August 25, 2026 study assessed 4,198 description/company pairs across matching settings. The publisher reports 86% good or better at Exact. This evaluates the method across queries; it does not audit this individual list. Recorded company descriptions, where available, help you judge each match yourself. Read the full methodology: how the lists are built and what the study measures.
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 displayed company carries at least one verified work email. RevenueBase tracks 8,388 professional contacts with verified work emails across the full matched dataset. 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.
Record context: Company records and descriptions can change. Check the company's website for its current services and locations.

Legacy system modernization firms by metro in the United Kingdom

Legacy system modernization firms in Manchester33

Frequently asked

What is RevenueBase SmartSearch?

RevenueBase SmartSearch finds niche companies by the meaning of their business descriptions in the RevenueBase company graph. Exact, Similar, Related and Broad control how closely companies must fit your description. This list uses Exact for “legacy system modernization firms”; each Exact match badge shows search membership, not an individual similarity or quality score.

How many legacy system modernization firms are there based in London, United Kingdom?

RevenueBase identified 386 company matches for legacy system modernization firms associated with London, United Kingdom as of September 2026, using the meaning of business descriptions at Exact. This is the recorded matched set in the RevenueBase company graph.

What is the largest company on this list?

Endava tops the displayed preview by professional contacts tracked in RevenueBase. Recorded headquarters appear in the company rows.

Which city in the United Kingdom has the most legacy system modernization firms?

London leads the United Kingdom with 386 company records, followed by Manchester (33) and Birmingham (18).

How do I get contact information for these companies?

A free RevenueBase account lets you run this exact search and work limited free results with 500 credits to start. Upgrading provides access to the 8,388 professional contacts with verified work emails tracked across these 386 companies; direct dials are available where recorded.

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 SmartSearch, 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.