Company lists · Data refreshed September 2026

Top 23 Electrical systems integration contractors based in London, United Kingdom

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

Compiled by the RevenueBase Data Team Data refreshed Sep 29, 2026 339 companies tracked

RevenueBase identified 339 electrical systems integration contractors headquartered in London, United Kingdom as of September 2026 and tracks 2,042 professional contacts across them, including 508 with verified work emails. Across the United Kingdom, London is the largest hub for this category.

This list covers electrical systems integration contractors 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 29, 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 29, 2026 86% judged on-target in blind review

339Companies

2,042Contacts tracked

508Verified emails

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The 23 largest electrical systems integration contractors based in London, United Kingdom

Ranked by team size

Top 23 of 339 electrical systems integration contractors based in London, United Kingdom, ranked by team size, largest first. Data refreshed Sep 29, 2026. RevenueBase Smart Search rates how each company's information relates to electrical systems integration contractors: 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	Grant Walker Engineering	Strong evidence	London, United KingdomHQ checked Sep 29, 2026	51-200	81 contacts →
	Strong evidence “Grant Walker Engineering specialise in the complete installation of Electrical and Mechanical systems across all work sectors including quality office developments, commercial and…” Source: RevenueBase Database · checked Sep 29, 2026
2	Malcolm Building Services Limited	Strong evidence	London, United KingdomHQ checked Sep 29, 2026	51-200	40 contacts →
	Strong evidence “Malcolm Building Services are a London based Mechanical and Electrical contractor specialising in Commercial & residential new build mixed use schemes.” Source: RevenueBase Database · checked Sep 29, 2026
3	Link Media Systems	Partial evidence	London, United KingdomHQ checked Sep 29, 2026	51-200	37 contacts →
	Partial evidence “We are systems integrators.” Source: RevenueBase Database · checked Sep 29, 2026
4	Redworx MEP Limited	Strong evidence	London, United KingdomHQ checked Sep 29, 2026	11-50	37 contacts →
	Strong evidence “About Us: Established in 2023, Redworx MEP Limited is a dynamic Mechanical and Electrical contractor aiming to make a significant impact in the London market.” Source: RevenueBase Database · checked Sep 29, 2026
5	Phoenix ME	Strong evidence	London, United KingdomHQ checked Sep 29, 2026	501-1,000	33 contacts →
	Strong evidence “We stand as a well-established industry leader, specialising in the design, installation, and commissioning of mechanical and electrical systems across diverse sectors.” Source: RevenueBase Database · checked Sep 29, 2026
6	Okto Technologies	Partial evidence	London, United KingdomHQ checked Sep 29, 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 29, 2026
7	ARC Electrical	Strong evidence	London, United KingdomHQ checked Sep 29, 2026	1-10	30 contacts →
	Strong evidence “Electrical Contractors and Wholesalers based in Central London and Essex.” Source: RevenueBase Database · checked Sep 29, 2026
8	Torpedo Factory Group	Partial evidence	London, United KingdomHQ checked Sep 29, 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 29, 2026
9	Leonari LTD	Strong evidence	London, United KingdomHQ checked Sep 29, 2026	11-50	25 contacts →
	Strong evidence “Established in 2014, Leonari is a Mechanical & Electrical contractor working in London and the South East.” Source: RevenueBase Database · checked Sep 29, 2026
10	Interlinked Group	Partial evidence	London, United KingdomHQ checked Sep 29, 2026	51-200	24 contacts →
	Partial evidence “Specialise in Electrical, AV/IT, Wireless Networks, Smart Buildings, Fire & Security in the construction sector, over the UK & Europe.” Source: RevenueBase Database · checked Sep 29, 2026
11	Niblock Electrical Services	Strong evidence	London, United KingdomHQ checked Sep 29, 2026	11-50	22 contacts →
	Strong evidence “Niblock Electrical Services are a M&E contractor based in South East London.” Source: RevenueBase Database · checked Sep 29, 2026
12	Dennis Johns Service Group	Partial evidence	London, United KingdomHQ checked Sep 29, 2026	51-200	20 contacts →
	Partial evidence “The Dennis Johns Service Group is a forward thinking group of companies providing, Electrical, CCTV and Access Control, installation and maintenance contracting services.” Source: RevenueBase Database · checked Sep 29, 2026
13	QQ Solutions LTD	Partial evidence	London, United KingdomHQ checked Sep 29, 2026	11-50	20 contacts →
	Partial evidence “QQ design, supply and install of residental and commercial automation technology and energy-efficient control systems.” Source: RevenueBase Database · checked Sep 29, 2026
14	SI Electrical LTD	Partial evidence	London, United KingdomHQ checked Sep 29, 2026	11-50	14 contacts →
	Partial evidence “SI Electrical provide complete electrical solutions and are renowned for our expertise in lighting and controls.” Source: RevenueBase Database · checked Sep 29, 2026
15	Twentytwo Integration	Strong evidence	London, United KingdomHQ checked Sep 29, 2026	11-50	12 contacts →
	Strong evidence “TwentyTwo Integration are experts in bringing together audio, television, lighting, telephone & communications, data networks, security & other bespoke systems into a unified…” Source: RevenueBase Database · checked Sep 29, 2026
16	Cole Group	Partial evidence	London, United KingdomHQ checked Sep 29, 2026	11-50	12 contacts →
	Partial evidence “At COLE Group, we specialize in delivering outstanding electrical solutions for both new build and refurbishment projects.” Source: RevenueBase Database · checked Sep 29, 2026
17	Concepto Solutions LTD	Partial evidence	London, United KingdomHQ checked Sep 29, 2026	11-50	12 contacts →
	Partial evidence “Concepto AV is an electrical-led technology company delivering high-quality electrical installations across residential and commercial projects in London.” Source: RevenueBase Database · checked Sep 29, 2026
18	SPL Construct LTD	Strong evidence	London, United KingdomHQ checked Sep 29, 2026	11-50	12 contacts →
	Strong evidence “As fully qualified, time served electrical contractors, we have a wealth of knowledge in the electrical industry, predominantly carrying out a wide range of services from design…” Source: RevenueBase Database · checked Sep 29, 2026
19	RJK Security Systems	Strong evidence	London, United KingdomHQ checked Sep 29, 2026	11-50	11 contacts →
	Strong evidence “RJK Security Systems are a specialist contractor and integrator of electronic security systems and Audio-Visual/Smarthome automation.” Source: RevenueBase Database · checked Sep 29, 2026
20	Intellicasa	Partial evidence	London, United KingdomHQ checked Sep 29, 2026	11-50	11 contacts →
	Partial evidence “We are an award-winning, SafeContractor approved company specialised in SMART automation technologies and entertainment systems for the residential and commercial sectors.” Source: RevenueBase Database · checked Sep 29, 2026
21	London Electrical Solutions LTD	Partial evidence	London, United KingdomHQ checked Sep 29, 2026	11-50	11 contacts →
	Partial evidence “London Electrical Solutions: Experienced Electricians operating across London Residential & Commercial Electricians serving Greater London London Electrical Solutions is a…” Source: RevenueBase Database · checked Sep 29, 2026
22	Zeus Electrical Constructions	Partial evidence	London, United KingdomHQ checked Sep 29, 2026	11-50	11 contacts →
	Partial evidence “ZEUS is engaged in studies and electrical installations.” Source: RevenueBase Database · checked Sep 29, 2026
23	TNS Electrical Contractors LTD	Strong evidence	London, United KingdomHQ checked Sep 29, 2026	11-50	11 contacts →
	Strong evidence “We are TNS Electrical Contractors Ltd and based in East London with over 15 years of experience in the electrical industry.” Source: RevenueBase Database · checked Sep 29, 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: electrical systems integration contractors. 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 electrical systems integration contractors.
Partial evidence: Its own public description names part of electrical systems integration contractors, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name electrical systems integration contractors. 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 23 of 339 electrical systems integration contractors based in London, United Kingdom

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Electrical systems integration contractors based in London, United Kingdom at a glance

As of Sep 29, 2026

24.9%Verified-email coverage

6.0Average contacts per company

1-10Median size (employees)

Sep 29, 2026Page data refreshed

Companies by employee count

1-10

209

11-50

100

51-200

201-500

501-1,000

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 339 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 electrical systems integration contractors, 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 “electrical systems integration contractors”. 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 electrical systems integration contractors), 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 electrical systems integration contractors, 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, 508 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 29, 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.

Electrical systems integration contractors by metro in the United Kingdom

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 electrical systems integration contractors, 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 electrical systems integration contractors are there based in London, United Kingdom?

RevenueBase identified 339 electrical systems integration contractors 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?

Grant Walker Engineering, headquartered in London, tops this list with the largest team on record.

Which city in the United Kingdom has the most electrical systems integration contractors?

London leads the United Kingdom with 339 headquartered companies, followed by Manchester (71) and Nottingham (58).

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 508 verified decision-maker contacts tracked across these 339 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 29, 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.