Company lists · Data refreshed September 2026
Top 25 Energy efficiency as a service companies based in the United Kingdom
RevenueBase identified 649 energy efficiency as a service companies headquartered in the United Kingdom as of September 2026 and tracks 19,816 professional contacts across them, including 6,524 with verified work emails. London is the largest hub.
This list covers energy efficiency as a service companies 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 21, 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 25 largest energy efficiency as a service companies based in the United Kingdom
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 9,238 contacts → | ||||
Indirect evidence “Taking care of things.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 2 | 2,627 contacts → | ||||
Strong evidence “We help businesses manage energy needs, boost efficiency, control costs and achieve decarbonisation goals for a better energy future.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 3 | 509 contacts → | ||||
Strong evidence “As leaders in our field, we’re trusted by over businesses to provide a full energy service.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 4 | 316 contacts → | ||||
Partial evidence “EIC Partnership: A Legacy of Expertise, A Commitment to Sustainability With origins dating back to 1975, EIC has cultivated nearly 50 years of distinguished service in energy and…” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 5 | 206 contacts → | ||||
Partial evidence “Who we are » The UK’s leading Energy Management company » Our aim is to increase energy performance within buildings » Deliver energy projects to maximise customer return on…” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 6 | 171 contacts → | ||||
Partial evidence “CFP Energy is a leading provider of energy and environmental solutions for industrial and commercial clients.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 7 | 159 contacts → | ||||
Partial evidence “At Consultiv Utilities, we help organisations to take control of their energy strategy and support them in navigating the complexities of energy, with confidence.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 8 | 142 contacts → | ||||
Partial evidence “Optimised exists to accelerate the shift to a low-carbon future by making energy management work; commercially, operationally and sustainably.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 9 | 125 contacts → | ||||
Partial evidence “Mitie Energy are an award-winning, UK-based energy, utilities and sustainability solutions business.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 10 | 124 contacts → | ||||
Partial evidence “We are an award-winning energy consultancy and certified B Corp™.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 11 | 122 contacts → | ||||
Partial evidence “Tritility is a UK business energy consultancy helping organisations reduce energy and overhead costs through smarter electricity, gas and water procurement.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 12 | 115 contacts → | ||||
Indirect evidence “At ZTP, we’re committed to accelerating the transition to a more sustainable future by reducing the negative impact of human activity on our planet - ecologically, financially…” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 13 | 106 contacts → | ||||
Partial evidence “Managing business energy can be overwhelming.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 14 | 102 contacts → | ||||
Partial evidence “Hometree is a home energy services company on a mission to accelerate the transition to net zero.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 15 | 98 contacts → | ||||
Strong evidence “eEnergy (AIM: EAAS) is a UK-based Energy-as-a-Service (EaaS) provider, funding and delivering energy-saving and energy-generating solutions across multi-site public sector and…” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 16 | 97 contacts → | ||||
Partial evidence “Best.Energy is a UK based company specialising in the measurement, control and reduction of energy consumption and costs within the industrial, commercial and public sectors.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 17 | 93 contacts → | ||||
Partial evidence “At LASER Energy, part of the Commercial Services Group Energy & Environment portfolio, a wholly-owned business unit of Kent County Council, we help public sector organisations…” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 18 | 90 contacts → | ||||
Partial evidence “The Green Energy Advice Bureau are a leading independent award-winning UK commercial energy consultancy.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 19 | 88 contacts → | ||||
Partial evidence “Ignite is dedicated to providing large UK multi-site energy users with a full suite of sustainability services.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 20 | 69 contacts → | ||||
Strong evidence “TEAM is the UK’s leading supplier of carbon and energy management solutions committed to driving the efficiency and sustainability of energy consumption and environmental…” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 21 | 67 contacts → | ||||
Indirect evidence “We’re a leading nationwide property services company established in 2013.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 22 | 66 contacts → | ||||
Partial evidence “We bring good energy to the table to help you save yours.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 23 | 62 contacts → | ||||
Strong evidence “Cenergist is a specialist energy and water efficiency company in the UK and Europe.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 24 | 61 contacts → | ||||
Partial evidence “Services we provide: Fixed Energy Procurement Flexible Energy Procurement Building Management Carbon Solutions Waste Management Invoice Validation (Electricity, Gas, Water)…” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 25 | 60 contacts → | ||||
Indirect evidence “Hello.” Source: RevenueBase Database · checked Sep 21, 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: energy efficiency as a service companies. 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 energy efficiency as a service companies.
- Partial evidence
- Its own public description names part of energy efficiency as a service companies, so it works in or next to the category without describing itself that way.
- Indirect evidence
- The description shown does not name energy efficiency as a service companies. 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 649 energy efficiency as a service companies based in the United Kingdom
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Energy efficiency as a service companies based in the United Kingdom at a glance
As of Sep 21, 2026Companies by employee count
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 649 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 energy efficiency as a service companies, 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 “energy efficiency as a service companies”. 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 energy efficiency as a service companies), 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 energy efficiency as a service companies, 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, 6,524 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 21, 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.
Energy efficiency as a service companies by metro
- Energy efficiency as a service companies in London95
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 energy efficiency as a service companies, 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 energy efficiency as a service companies are there based in the United Kingdom?
RevenueBase identified 649 energy efficiency as a service companies 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?
British GAS, headquartered in Windsor, tops this list with the largest team on record.
Which city has the most energy efficiency as a service companies?
London leads with 95 headquartered companies, followed by Manchester (21) and Birmingham (13).
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 6,524 verified decision-maker contacts tracked across these 649 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 21, 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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