Company lists · Data refreshed September 2026

Top 25 High voltage contractors based in the United Kingdom

Name: High voltage contractors based in the United Kingdom
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 16, 2026 861 companies tracked

RevenueBase identified 861 high voltage contractors headquartered in the United Kingdom as of September 2026 and tracks 7,336 professional contacts across them, including 1,940 with verified work emails. London is the largest hub.

This list covers high voltage contractors 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 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.

How to read this list HQ checked on every row RevenueBase Smart Search rating on every row Refreshed Sep 16, 2026 86% judged on-target in blind review

861Companies

7,336Contacts tracked

1,940Verified emails

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The 25 largest high voltage contractors based in the United Kingdom

Ranked by team size

Top 25 of 861 high voltage contractors based in the United Kingdom, ranked by team size, largest first. Data refreshed Sep 16, 2026. RevenueBase Smart Search rates how each company's information relates to high voltage 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	Freedom	Indirect evidence	Leeds, United KingdomHQ checked Sep 16, 2026	1,001-5,000	664 contacts →
	Indirect evidence “Freedom is a leading provider of facilities and power engineering services.” Source: RevenueBase Database · checked Sep 16, 2026
2	PN Daly Limited	Indirect evidence	Rochdale, United KingdomHQ checked Sep 16, 2026	501-1,000	141 contacts →
	Indirect evidence “P.N.” Source: RevenueBase Database · checked Sep 16, 2026
3	Powersystems	Indirect evidence	Bristol, United KingdomHQ checked Sep 16, 2026	51-200	126 contacts →
	Indirect evidence “Powered by People.” Source: RevenueBase Database · checked Sep 16, 2026
4	Excalon LTD	Indirect evidence	Salford, United KingdomHQ checked Sep 16, 2026	201-500	108 contacts →
	Indirect evidence “Excalon is one of the Britain’s leading UK Electrical Utility Service Providers.” Source: RevenueBase Database · checked Sep 16, 2026
5	Rock Power Connections LTD	Indirect evidence	Bromsgrove, United KingdomHQ checked Sep 16, 2026	51-200	105 contacts →
	Indirect evidence “Rock Power Connections are experts in electrical connections with a proven track record of quality and safety.” Source: RevenueBase Database · checked Sep 16, 2026
6	Sinewave	Strong evidence	Swindon, United KingdomHQ checked Sep 16, 2026	51-200	96 contacts →
	Strong evidence “Sinewave are a specialist engineering company who provide High and Low voltage electrical services across the UK.” Source: RevenueBase Database · checked Sep 16, 2026
7	GTDS	Indirect evidence	Hill, United KingdomHQ checked Sep 16, 2026	51-200	82 contacts →
	Indirect evidence “GTDS was established in July 2004 to provide specialist installation and commissioning services to the major manufacturers, National Grid and the Distribution Network Operators…” Source: RevenueBase Database · checked Sep 16, 2026
8	AKD	Indirect evidence	Edinburgh, United KingdomHQ checked Sep 16, 2026	51-200	79 contacts →
	Indirect evidence “AKD’s clients get quick results, normally leading to reduced costs and gaining an improved service.” Source: RevenueBase Database · checked Sep 16, 2026
9	AUS LTD	Indirect evidence	Clayton West, United KingdomHQ checked Sep 16, 2026	51-200	63 contacts →
	Indirect evidence “AUS is a specialist supplier to the electricity distribution and transmission, rail, utility arboricultural, and telecommunications industries.” Source: RevenueBase Database · checked Sep 16, 2026
10	Avidety	Indirect evidence	Sittingbourne, United KingdomHQ checked Sep 16, 2026	51-200	56 contacts →
	Indirect evidence “Avidety specialise in the construction and maintenance of overhead and underground electricity networks.” Source: RevenueBase Database · checked Sep 16, 2026
11	Hvss High Voltage Substation Services LTD	Strong evidence	Watford, United KingdomHQ checked Sep 16, 2026	11-50	55 contacts →
	Strong evidence “HVSS (High Voltage Substation Services) was formed in 2009 specializing in installation and commissioning of High Voltage Substations Systems up to 400kV.” Source: RevenueBase Database · checked Sep 16, 2026
12	Energy And System Technical LTD East Solutions	Strong evidence	Downham Market, United KingdomHQ checked Sep 16, 2026	51-200	48 contacts →
	Strong evidence “High Voltage Engineers providing services in High Voltage Maintenance, Operations and Installation to private network operators both on and offshore.” Source: RevenueBase Database · checked Sep 16, 2026
13	Lloyd Morris Electrical LTD	Indirect evidence	Wrexham, United KingdomHQ checked Sep 16, 2026	51-200	47 contacts →
	Indirect evidence “Lloyd Morris Electrical Limited is a company of Electrical Engineers, specialising in the design, manufacture and installation of Electrical Distribution and Control Systems for…” Source: RevenueBase Database · checked Sep 16, 2026
14	Acrastyle Limited	Strong evidence	Ulverston, United KingdomHQ checked Sep 16, 2026	51-200	43 contacts →
	Strong evidence “Acrastyle Limited (UK) is a resource-rich engineering company that designs, manufactures, tests, installs, commissions, and maintains high-voltage sub-station protection and…” Source: RevenueBase Database · checked Sep 16, 2026
15	Jlec Electrical LTD	Indirect evidence	Bradford, United KingdomHQ checked Sep 16, 2026	11-50	38 contacts →
	Indirect evidence “JLEC Electrical is committed to providing premium quality along with competitive service to all customers new and old.” Source: RevenueBase Database · checked Sep 16, 2026
16	EMI Co. LTD	Indirect evidence	Gainsborough, United KingdomHQ checked Sep 16, 2026	51-200	37 contacts →
	Indirect evidence “Keeping power, water, and rail moving since 1966.” Source: RevenueBase Database · checked Sep 16, 2026
17	EDS HV Group	Strong evidence	Haslingden, United KingdomHQ checked Sep 16, 2026	51-200	37 contacts →
	Strong evidence “High Voltage Engineering Solutions, from conceptual design, through to installation and O&M.” Source: RevenueBase Database · checked Sep 16, 2026
18	Lagan Energy Engineering LTD	Indirect evidence	Omagh, United KingdomHQ checked Sep 16, 2026	51-200	36 contacts →
	Indirect evidence “Lagan Energy Engineering Ltd provides quality assured electrical engineering, contracting and consultancy services to customers on various continents.” Source: RevenueBase Database · checked Sep 16, 2026
19	Substation Engineering Services LTD	Strong evidence	Stafford, United KingdomHQ checked Sep 16, 2026	11-50	36 contacts →
	Strong evidence “Specialising in High Voltage Substation Installation & Commissioning, Site & Project Management, Refurbishment, Maintenance, SES Ltd has established a solid reputation for…” Source: RevenueBase Database · checked Sep 16, 2026
20	Durkin And Sons Power And Civil Engineers	Indirect evidence	Perivale, United KingdomHQ checked Sep 16, 2026	51-200	35 contacts →
	Indirect evidence “Durkin and Sons have for 40 years been a go-to partner for National Grid, and DNO organisations, who continue to entrust the delivery of large HV & EHV cabling projects to us.” Source: RevenueBase Database · checked Sep 16, 2026
21	Aardvarc Electrical Engineers LTD	Strong evidence	Hebburn, United KingdomHQ checked Sep 16, 2026	51-200	33 contacts →
	Strong evidence “High Voltage Specialists” Source: RevenueBase Database · checked Sep 16, 2026
22	TSG Powertek	Partial evidence	Paisley, United KingdomHQ checked Sep 16, 2026	51-200	33 contacts →
	Partial evidence “Powertek Utilities (a TSG UK Company) offer a comprehensive cable jointing and cable installation service at voltages up to and including 33kV, to DNO, IDNOs, ICPs and private…” Source: RevenueBase Database · checked Sep 16, 2026
23	ADI Electrical	Partial evidence	Kings Norton, United KingdomHQ checked Sep 16, 2026	201-500	32 contacts →
	Partial evidence “adi Electrical have been delivering high quality and reliable Electrical Installation services for over 25 years.” Source: RevenueBase Database · checked Sep 16, 2026
24	KUS Power Engineering	Strong evidence	Moreton In Marsh, United KingdomHQ checked Sep 16, 2026	11-50	32 contacts →
	Strong evidence “A design and build high voltage electrical contractor delivering turnkey substation projects from 11kV to 275kV.” Source: RevenueBase Database · checked Sep 16, 2026
25	Mmes 2012 Limited	Indirect evidence	Bridgwater, United KingdomHQ checked Sep 16, 2026	51-200	31 contacts →
	Indirect evidence “MMES 2012 LTD is an Electrical Installation Company.” Source: RevenueBase Database · checked Sep 16, 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: high voltage 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 high voltage contractors.
Partial evidence: Its own public description names part of high voltage contractors, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name high voltage 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 25 of 861 high voltage contractors based in the United Kingdom

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High voltage contractors based in the United Kingdom at a glance

As of Sep 16, 2026

26.4%Verified-email coverage

8.5Average contacts per company

1-10Median size (employees)

4.4%Largest-city concentration · London

Sep 16, 2026Page data refreshed

Companies by employee count

1-10

494

11-50

299

51-200

201-500

501-1,000

1,001-5,000

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 861 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 high voltage 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 the United Kingdom whose own description of what they do matches “high voltage 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 high voltage 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 high voltage contractors, 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, 1,940 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.

High voltage contractors by metro

High voltage contractors in London38

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 high voltage 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 high voltage contractors are there based in the United Kingdom?

RevenueBase identified 861 high voltage contractors 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?

Freedom, headquartered in Leeds, tops this list with the largest team on record.

Which city has the most high voltage contractors?

London leads with 38 headquartered companies, followed by Manchester (21) and Bristol (11).

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 1,940 verified decision-maker contacts tracked across these 861 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.