Company lists · Data verified August 2026

Top 25 Energy efficiency consulting firms based in the United Kingdom

Name: Energy efficiency consulting firms based in the United Kingdom
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Verified Aug 28, 2026 864 companies tracked

There are 864 energy efficiency consulting firms headquartered in the United Kingdom (RevenueBase, August 2026). RevenueBase tracks 16,836 professional contacts across them, including 6,063 with verified work emails and 749 with mobile numbers. London is the largest hub.

This list covers energy efficiency consulting firms headquartered in the United Kingdom, matched on what each company actually does as described in its own words. Ranked by team size, largest first. Data current as of August 28, 2026.

864Companies

16,836Contacts tracked

6,063Verified emails

749Mobile numbers

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The 25 largest energy efficiency consulting firms based in the United Kingdom

Ranked by team size

Top 25 of 864 energy efficiency consulting firms based in the United Kingdom, ranked by team size, largest first. Data verified Aug 28, 2026. Click a count to unlock that company's people.
#	Company	HQ	Employees	Contacts	Verified emails
1	British GAS	Staines	10001+	9,287	2,729
2	Atelier TEN	London	51-200	321	229
3	EIC Partnership	Redditch	51-200	315	56
4	CFP Energy	London	201-500	177	95
5	Consultiv Utilities	Hebburn	201-500	156	116
6	Optimised	Bristol	51-200	139	107
7	Consultus	Rochford	51-200	127	106
8	Mitie Energy	London	51-200	126	48
9	AMBER	Cardiff	51-200	123	87
10	Tritility	Jarrow	51-200	122	88
11	ZTP	London	51-200	116	62
12	TROO	n/a	51-200	104	74
13	The Green Energy Advice Bureau	Sunderland	51-200	98	39
14	Katoni Engineering	Aberdeen	51-200	90	63
15	Sustainable Advantage	London	51-200	88	55
16	Team Energy Auditing Agency LTD	Milton Keynes	51-200	70	31
17	Birdsall Group LTD	East Grinstead	51-200	64	27
18	Cenergist	Washington	201-500	63	35
19	RYBKA	Edinburgh	51-200	61	45
20	RSP Consulting Engineers	Aberdeen	51-200	60	19
21	Energy Drive	London	51-200	59	19
22	Method Consulting	Cardiff	51-200	53	39
23	Fusion For Business	Durham	51-200	49	34
24	ECBS	Hebburn	51-200	47	17
25	Pace Global, A Siemens Business	Camberley	51-200	38	6

Showing 25 of 864 energy efficiency consulting firms based in the United Kingdom

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Energy efficiency consulting firms based in the United Kingdom at a glance

As of Aug 28, 2026

1-10Median size (employees)

LondonLargest hub · 135 HQs

749Contacts with mobile numbers

0Emails re-verified in last 30 days

Companies by employee count

1-10

548

11-50

243

51-200

201-500

1,001-5,000

5,001-10,000

10001+

Energy efficiency consulting firms by metro

Metro	Companies
Energy efficiency consulting firms in London	135
Energy efficiency consulting firms in Manchester	26
Energy efficiency consulting firms in Nottingham	17
Energy efficiency consulting firms in Bristol	14
Energy efficiency consulting firms in Leeds	14
Energy efficiency consulting firms in Birmingham	12
Energy efficiency consulting firms in Edinburgh	11

How this list was built

Source: The RevenueBase company graph: 21.3 million companies and 398.9 million professional contacts resolved from primary sources.
Inclusion: Companies whose own business descriptions match “energy efficiency consulting firms”, with match quality audited by blind human judging, and headquartered in the United Kingdom.
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: Contact records re-verify on a rolling cadence; 0 contacts on this list were re-verified in the last 30 days.
Refresh: Lists are refreshed periodically as the underlying company graph is re-verified. Last verified Aug 28, 2026.

Frequently asked

How many energy efficiency consulting firms are there based in the United Kingdom?

There are 864 energy efficiency consulting firms headquartered in the United Kingdom as of August 2026 (RevenueBase).

What is the largest company on this list?

British GAS, headquartered in Staines, tops this list with the largest team on record.

Which city has the most energy efficiency consulting firms?

London leads with 135 headquartered companies, followed by Manchester (26) and Nottingham (17).

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 6,063 verified decision-maker contacts tracked across these 864 companies.

How current is this list?

The list is refreshed periodically as the underlying company graph is re-verified. It was last verified on August 28, 2026.

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About this data

RevenueBase is a B2B contact data platform. Its company graph covers 21.3 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, the same data that powers RevenueBase's B2B data products and the free research portal.