Company lists · Data refreshed September 2026
Top 23 Commercial electrical contractors based in London, United Kingdom
RevenueBase identified 322 commercial electrical contractors headquartered in London, United Kingdom as of September 2026 and tracks 1,602 professional contacts across them, including 470 with verified work emails. London is the largest hub.
This list covers commercial electrical 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 16, 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.
The 23 largest commercial electrical contractors based in London, United Kingdom
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 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 16, 2026Thanks. The Data Team will review it. | |||||
| 2 | 75 contacts → | ||||
Strong evidence “Maze Engineering was established in 2003 and provides refurbishment, maintenance and fit out mechanical and electrical services in the commercial, industrial, education and…” Source: RevenueBase Database · checked Sep 16, 2026Thanks. The Data Team will review it. | |||||
| 3 | 42 contacts → | ||||
Partial evidence “The core activities of our business are all aspects of mechanical and electrical services including air conditioning, sprinkler systems, CHW<HW, ventilation, BMS, door entry and…” Source: RevenueBase Database · checked Sep 16, 2026Thanks. The Data Team will review it. | |||||
| 4 | 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 16, 2026Thanks. The Data Team will review it. | |||||
| 5 | 34 contacts → | ||||
Partial evidence “Hanover is an award-winning building services provider that specialises in electrical, mechanical, plumbing, heating and renewable energy installations.” Source: RevenueBase Database · checked Sep 16, 2026Thanks. The Data Team will review it. | |||||
| 6 | 33 contacts → | ||||
Partial 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 16, 2026Thanks. The Data Team will review it. | |||||
| 7 | 30 contacts → | ||||
Strong evidence “Electrical Contractors and Wholesalers based in Central London and Essex.” Source: RevenueBase Database · checked Sep 16, 2026Thanks. The Data Team will review it. | |||||
| 8 | 29 contacts → | ||||
Strong evidence “We are one of the leading plumbing, heating and electrical companies nationally, serving residential and commercial clients throughout South East England With almost three decades…” Source: RevenueBase Database · checked Sep 16, 2026Thanks. The Data Team will review it. | |||||
| 9 | 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 16, 2026Thanks. The Data Team will review it. | |||||
| 10 | 22 contacts → | ||||
Strong evidence “Niblock Electrical Services are a M&E contractor based in South East London.” Source: RevenueBase Database · checked Sep 16, 2026Thanks. The Data Team will review it. | |||||
| 11 | 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 16, 2026Thanks. The Data Team will review it. | |||||
| 12 | 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 16, 2026Thanks. The Data Team will review it. | |||||
| 13 | 14 contacts → | ||||
Partial evidence “Our core offerings are split into three main business streams, Mechanical, Electrical & Fit-out.” Source: RevenueBase Database · checked Sep 16, 2026Thanks. The Data Team will review it. | |||||
| 14 | 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 16, 2026Thanks. The Data Team will review it. | |||||
| 15 | 12 contacts → | ||||
Strong 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 16, 2026Thanks. The Data Team will review it. | |||||
| 16 | 12 contacts → | ||||
Indirect evidence “At GPM London, we specialise in delivering hassle-free, professional MEP solutions tailored to your needs, no matter the size or complexity of the job.” Source: RevenueBase Database · checked Sep 16, 2026Thanks. The Data Team will review it. | |||||
| 17 | 12 contacts → | ||||
Partial evidence “Here at Rederic, we leverage our wealth of industry knowledge and expertise to provide efficient, personalised solutions for all mechanical & electrical, audiovisual, data…” Source: RevenueBase Database · checked Sep 16, 2026Thanks. The Data Team will review it. | |||||
| 18 | 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 16, 2026Thanks. The Data Team will review it. | |||||
| 19 | 11 contacts → | ||||
Strong 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 16, 2026Thanks. The Data Team will review it. | |||||
| 20 | 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 16, 2026Thanks. The Data Team will review it. | |||||
| 21 | 9 contacts → | ||||
Strong evidence “Intrelec are NICEIC Approved Mechanical & Electrical Contractors in London providing M&E design, installation and maintenance services to commercial, industrial and residential…” Source: RevenueBase Database · checked Sep 16, 2026Thanks. The Data Team will review it. | |||||
| 22 | 9 contacts → | ||||
Strong evidence “JSJ Smart Homes was formed as a specialised contractor in the field of domestic installations, covering all aspects of electrical installs, such as home automation and data…” Source: RevenueBase Database · checked Sep 16, 2026Thanks. The Data Team will review it. | |||||
| 23 | 9 contacts → | ||||
Strong evidence “Chadwell’s is a multi-faceted commercial property maintenance and installation specialist, offering electrical, mechanical and building solutions.” Source: RevenueBase Database · checked Sep 16, 2026Thanks. The Data Team will review it. | |||||
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: commercial electrical 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 commercial electrical contractors.
- Partial evidence
- Its own public description names part of commercial electrical contractors, so it works in or next to the category without describing itself that way.
- Indirect evidence
- The description shown does not name commercial electrical 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 322 commercial electrical contractors based in London, United Kingdom
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Commercial electrical contractors based in London, United Kingdom at a glance
As of Sep 16, 2026Companies by employee count
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 322 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 commercial electrical 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 “commercial electrical 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 commercial electrical 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 commercial electrical 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, 470 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 16, 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.
Commercial electrical contractors by metro in the United Kingdom
- Commercial electrical contractors in London322
- Commercial electrical contractors in Bristol55
- Commercial electrical contractors in Nottingham53
- Commercial electrical contractors in Manchester52
- Commercial electrical contractors in Birmingham48
- Commercial electrical contractors in Leeds43
- Commercial electrical contractors in Glasgow38
- Commercial electrical contractors in Sheffield37
- Commercial electrical contractors in Southampton36
- Commercial electrical contractors in Hull35
- Commercial electrical contractors in Leicester35
- Commercial electrical contractors in Liverpool31
- Commercial electrical contractors in Northampton26
- Commercial electrical contractors in Gloucester25
- Commercial electrical contractors in Portsmouth25
- Commercial electrical contractors in Warrington25
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 commercial electrical 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 commercial electrical contractors are there based in London, United Kingdom?
RevenueBase identified 322 commercial electrical 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 has the most commercial electrical contractors?
London leads with 322 headquartered companies, followed by Bristol (55) and Nottingham (53).
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 470 verified decision-maker contacts tracked across these 322 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 16, 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.
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