Company lists · Data refreshed September 2026

Top 25 Substation inspection services based in the United Kingdom

Name: Substation inspection services based in the United Kingdom
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 22, 2026 277 companies tracked

RevenueBase identified 277 substation inspection services headquartered in the United Kingdom as of September 2026 and tracks 2,130 professional contacts across them, including 776 with verified work emails. London is the largest hub.

This list covers substation inspection services 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 22, 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 22, 2026 86% judged on-target in blind review

277Companies

2,130Contacts tracked

776Verified emails

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The 25 largest substation inspection services based in the United Kingdom

Ranked by team size

Top 25 of 277 substation inspection services based in the United Kingdom, ranked by team size, largest first. Data refreshed Sep 22, 2026. RevenueBase Smart Search rates how each company's information relates to substation inspection services: 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	Quartzelec Limited	Indirect evidence	Rugby, United KingdomHQ checked Sep 22, 2026	501-1,000	412 contacts →
	Indirect evidence “Quartzelec is a leading independent electrical engineering group delivering solutions and services in both UK and global markets.” Source: RevenueBase Database · checked Sep 22, 2026
2	AUS LTD	Indirect evidence	Clayton West, United KingdomHQ checked Sep 22, 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 22, 2026
3	Hvss High Voltage Substation Services LTD	Partial evidence	Watford, United KingdomHQ checked Sep 22, 2026	11-50	55 contacts →
	Partial 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 22, 2026
4	The Wiggett Group LTD	Indirect evidence	Brentwood, United KingdomHQ checked Sep 22, 2026	201-500	51 contacts →
	Indirect evidence “Wiggett Electrical has gone from strength to strength.” Source: RevenueBase Database · checked Sep 22, 2026
5	Acrastyle Limited	Indirect evidence	Ulverston, United KingdomHQ checked Sep 22, 2026	51-200	43 contacts →
	Indirect 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 22, 2026
6	Calbarrie Compliance Services LTD	Indirect evidence	Cheltenham, United KingdomHQ checked Sep 22, 2026	51-200	42 contacts →
	Indirect evidence “Calbarrie Compliance Services Ltd (Calbarrie) is the UK’s market leader in electrical compliance services and has been trading within the Health & Safety and Compliance sectors…” Source: RevenueBase Database · checked Sep 22, 2026
7	Cenelec Standards Inspections LTD	Partial evidence	Cramlington, United KingdomHQ checked Sep 22, 2026	51-200	42 contacts →
	Partial evidence “Cenelec Standards Inspections specialise in Electrical, Instrument and Mechanical Hazardous Area Inspection and Maintenance for clients in need of support to comply with the…” Source: RevenueBase Database · checked Sep 22, 2026
8	F.E.S. EX Limited	Indirect evidence	Grimsby, United KingdomHQ checked Sep 22, 2026	51-200	39 contacts →
	Indirect evidence “Established over 20 years ago by our Chairman, F.E.S.(EX) is a leading provider of a range of E, I&M services for all industries across both hazardous and non- hazardous…” Source: RevenueBase Database · checked Sep 22, 2026
9	EMI Co. LTD	Indirect evidence	Gainsborough, United KingdomHQ checked Sep 22, 2026	51-200	37 contacts →
	Indirect evidence “Keeping power, water, and rail moving since 1966.” Source: RevenueBase Database · checked Sep 22, 2026
10	Substation Engineering Services LTD	Partial evidence	Stafford, United KingdomHQ checked Sep 22, 2026	11-50	36 contacts →
	Partial 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 22, 2026
11	Group Management Electrical Surveys Limited	Partial evidence	Halifax, United KingdomHQ checked Sep 22, 2026	11-50	32 contacts →
	Partial evidence “For the last 25 years, Group Management Electrical Surveys have been providing Electrical Inspection, Test and Documentation services to many of the UK's leading companies.” Source: RevenueBase Database · checked Sep 22, 2026
12	Ashby Electrical Limited	Partial evidence	Pelsall, United KingdomHQ checked Sep 22, 2026	11-50	30 contacts →
	Partial evidence “Ashby Electrical provide a complete range of electrical design, installation, testing, inspection and maintenance services nationwide.” Source: RevenueBase Database · checked Sep 22, 2026
13	Novus Compliance Services Limited	Partial evidence	Bishop Stortford, United KingdomHQ checked Sep 22, 2026	51-200	21 contacts →
	Partial evidence “At Novus Compliance Services Ltd we specialise in Electrical Testing and Inspection, Maintenance, Installation design, Energy Management and refurbishment for a wide range of…” Source: RevenueBase Database · checked Sep 22, 2026
14	EML Electrical Contractors LTD	Indirect evidence	Peterborough, United KingdomHQ checked Sep 22, 2026	11-50	21 contacts →
	Indirect evidence “Here at EML Electrical we pride ourselves on providing quality installations at a competitive price.” Source: RevenueBase Database · checked Sep 22, 2026
15	HK Engineering LTD	Indirect evidence	Melksham, United KingdomHQ checked Sep 22, 2026	11-50	20 contacts →
	Indirect evidence “HK Engineering Ltd is a leading engineering company specialising in electrical and gas testing and innovative solutions, with a solid commitment to excellence.” Source: RevenueBase Database · checked Sep 22, 2026
16	Site Energy Services Limited	Indirect evidence	Newcastle Under Lyme, United KingdomHQ checked Sep 22, 2026	11-50	20 contacts →
	Indirect evidence Source: RevenueBase Database · checked Sep 22, 2026
17	Valen Power Engineering LTD	Indirect evidence	Manchester, United KingdomHQ checked Sep 22, 2026	11-50	19 contacts →
	Indirect evidence “Valen Power Engineering Ltd provides electrical engineering solutions for systems ranging from LV to 400kV.” Source: RevenueBase Database · checked Sep 22, 2026
18	GTR Transmission & Protection Solutions LTD	Partial evidence	Poole, United KingdomHQ checked Sep 22, 2026	11-50	17 contacts →
	Partial evidence “GTR Transmission & Protection Solutions Ltd is a registered engineering company and supplier of high voltage Commissioning Engineers for power stations & substations.” Source: RevenueBase Database · checked Sep 22, 2026
19	Winshall LTD	Partial evidence	Llantrisant, United KingdomHQ checked Sep 22, 2026	11-50	17 contacts →
	Partial evidence “Substation Project Support: Project & Site Management, Civils & M&E Installation Teams.” Source: RevenueBase Database · checked Sep 22, 2026
20	Power Engineering Services	Partial evidence	Wortley, United KingdomHQ checked Sep 22, 2026	11-50	16 contacts →
	Partial evidence “Unique in its operations, PES engineers substation equipment at its Leeds-based production facility, providing turnkey private network installation, independent contestable…” Source: RevenueBase Database · checked Sep 22, 2026
21	Redas Engineering & Construction	Partial evidence	Staffordshire, United KingdomHQ checked Sep 22, 2026	11-50	16 contacts →
	Partial evidence “REDAS Engineering & Construction is a team of experienced professionals with more than a decade experience in substation tendering, procurement, design, Installation, and…” Source: RevenueBase Database · checked Sep 22, 2026
22	PSS Power Engineering LTD	Indirect evidence	Winchester, United KingdomHQ checked Sep 22, 2026	11-50	15 contacts →
	Indirect evidence “PSS POWER ENGINEERING LTD is a high-voltage electrical engineering company based in South East England, United Kingdom.” Source: RevenueBase Database · checked Sep 22, 2026
23	Aylesford Electrical Contractors LTD	Indirect evidence	Maidstone, United KingdomHQ checked Sep 22, 2026	11-50	14 contacts →
	Indirect evidence “Aylesford Electrical is a specialist testing, maintenance and installation provider based in Kent.” Source: RevenueBase Database · checked Sep 22, 2026
24	Clearwater Electrical LTD	Indirect evidence	Portlethen, United KingdomHQ checked Sep 22, 2026	11-50	13 contacts →
	Indirect evidence “Clearwater Electrical Ltd is an Aberdeen-based company consisting of a team of Electrical Engineers with a wealth of experience in Electrical Contracting and Offshore Oil & Gas…” Source: RevenueBase Database · checked Sep 22, 2026
25	AJ Electrical Services	Indirect evidence	Fareham, United KingdomHQ checked Sep 22, 2026	11-50	13 contacts →
	Indirect evidence “AJ Electrical Services are renowned for quality and reliable electrical installations and maintenance within the commercial, industrial and rail industry.” Source: RevenueBase Database · checked Sep 22, 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: substation inspection services. 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 substation inspection services.
Partial evidence: Its own public description names part of substation inspection services, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name substation inspection services. 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 277 substation inspection services based in the United Kingdom

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Substation inspection services based in the United Kingdom at a glance

As of Sep 22, 2026

36.4%Verified-email coverage

7.7Average contacts per company

1-10Median size (employees)

7.2%Largest-city concentration · London

Sep 22, 2026Page data refreshed

Companies by employee count

1-10

170

11-50

51-200

201-500

501-1,000

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 277 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 substation inspection services, 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 “substation inspection services”. 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 substation inspection services), 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 substation inspection services, 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, 776 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 22, 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.

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 substation inspection services, 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 substation inspection services are there based in the United Kingdom?

RevenueBase identified 277 substation inspection services 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?

Quartzelec Limited, headquartered in Rugby, tops this list with the largest team on record.

Which city has the most substation inspection services?

London leads with 20 headquartered companies, followed by Manchester (6) and Belfast (3).

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 776 verified decision-maker contacts tracked across these 277 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 22, 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.