Company lists · Data refreshed September 2026

Top 25 Counterintelligence consulting firms based in the United Kingdom

RevenueBase identified 327 counterintelligence consulting firms headquartered in the United Kingdom as of September 2026 and tracks 3,087 professional contacts across them, including 1,181 with verified work emails. London is the largest hub.

This list covers counterintelligence 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. Every row shows the company's own description, its RevenueBase Smart Search rating, and when it was last checked. Data refreshed September 27, 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 27, 2026 86% judged on-target in blind review
327Companies
3,087Contacts tracked
1,181Verified emails
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The 25 largest counterintelligence consulting firms based in the United Kingdom

Ranked by team size
Top 25 of 327 counterintelligence consulting firms based in the United Kingdom, ranked by team size, largest first. Data refreshed Sep 27, 2026. RevenueBase Smart Search rates how each company's information relates to counterintelligence consulting firms: 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.
#CompanyRevenueBase Smart SearchHeadquartersEmployeesContacts
1Indirect evidenceLondon, United KingdomHQ checked Sep 27, 2026201-500351 contacts →

Indirect evidence

“S-RM is a global intelligence and cyber security consultancy.”

Source: RevenueBase Database · checked Sep 27, 2026
2Indirect evidenceGlobal, United KingdomHQ checked Sep 27, 2026201-500289 contacts →

Indirect evidence

“Sibylline is the world’s leading private consultancy for geopolitical risk, intelligence, and strategic insight, dedicated to helping leaders and organisations anticipate change…”

Source: RevenueBase Database · checked Sep 27, 2026
3Indirect evidenceLondon, United KingdomHQ checked Sep 27, 202651-200177 contacts →

Indirect evidence

“Whether you’re a business or an individual, digital threats to your precious data and assets can come in any form - external or internal.”

Source: RevenueBase Database · checked Sep 27, 2026
4Indirect evidence12 Arthur Street, United KingdomHQ checked Sep 27, 202651-200161 contacts →

Indirect evidence

“Schillings deploys a unique combination of expertise to help you handle high stakes opportunities and threats, because we believe everyone has a right to fair treatment of their…”

Source: RevenueBase Database · checked Sep 27, 2026
5Indirect evidenceLondon, United KingdomHQ checked Sep 27, 202651-200117 contacts →

Indirect evidence

“FACT are at the forefront of investigative and intelligence services, recognised by organisations, law enforcement, and governments worldwide.”

Source: RevenueBase Database · checked Sep 27, 2026
6Indirect evidenceLondon, United KingdomHQ checked Sep 27, 202651-20077 contacts →

Indirect evidence

“White Hat, part of the EPAM group, is an award-winning cyber intelligence and offensive security company that leverages an attacker’s perspective to shape innovative, proactive…”

Source: RevenueBase Database · checked Sep 27, 2026
7Indirect evidenceHigh Wycombe, United KingdomHQ checked Sep 27, 202651-20074 contacts →

Indirect evidence

“Saepio increase awareness, reduce risk and improve security in a continually evolving threat landscape.”

Source: RevenueBase Database · checked Sep 27, 2026
8Indirect evidenceLondon, United KingdomHQ checked Sep 27, 202651-20064 contacts →

Indirect evidence

“We provide intelligence, advisory and investigative services to investors, companies and NGOs grappling with the world's most important issues.”

Source: RevenueBase Database · checked Sep 27, 2026
9Indirect evidenceLondon, United KingdomHQ checked Sep 27, 202651-20062 contacts →

Indirect evidence

“Prevail Partners are mission-enablers.”

Source: RevenueBase Database · checked Sep 27, 2026
10Indirect evidenceLondon, United KingdomHQ checked Sep 27, 202651-20060 contacts →

Indirect evidence

“We provide deep expertise with technical and business specialists to help clients secure and protect the UK.”

Source: RevenueBase Database · checked Sep 27, 2026
11Indirect evidenceAlderley Edge, United KingdomHQ checked Sep 27, 202651-20057 contacts →

Indirect evidence

“CyberLab is the UK-leading cyber security consultancy and managed services provider, trusted by over 1,200 enterprise businesses, government departments, and household names to…”

Source: RevenueBase Database · checked Sep 27, 2026
12Indirect evidenceLondon, United KingdomHQ checked Sep 27, 2026n/a50 contacts →

Indirect evidence

“Dragonfly is a geopolitical and security intelligence service for the world’s leading organisations.”

Source: RevenueBase Database · checked Sep 27, 2026
13Partial evidenceLondon, United KingdomHQ checked Sep 27, 202611-5039 contacts →

Partial evidence

“SECFORCE are vendor independent offensive security specialists providing effective business risk intelligence and strategic security consulting.”

Source: RevenueBase Database · checked Sep 27, 2026
14Indirect evidenceLondon, United KingdomHQ checked Sep 27, 202651-20033 contacts →

Indirect evidence

“Othrys is a global strategic and risk advisory firm founded in 2016.”

Source: RevenueBase Database · checked Sep 27, 2026
15Indirect evidenceOxford, United KingdomHQ checked Sep 27, 202611-5029 contacts →

Indirect evidence

“Horus is a leading intelligence and security consultancy with a global, multilingual team of unrivalled experience, insight and operational expertise.”

Source: RevenueBase Database · checked Sep 27, 2026
16Indirect evidenceAltrincham, United KingdomHQ checked Sep 27, 202611-5026 contacts →

Indirect evidence

“Based in Manchester UK, we are an independent Cyber Security Consultancy providing Security services across a wide range of markets, from multi-national Corporate Organisations…”

Source: RevenueBase Database · checked Sep 27, 2026
17Indirect evidenceLondon, United KingdomHQ checked Sep 27, 202611-5023 contacts →

Indirect evidence

“Sastre is a research consultancy, a global collective of multi-lingual corporate investigations professionals and public policy analysts who specialise in modern open source…”

Source: RevenueBase Database · checked Sep 27, 2026
18Indirect evidenceLondon, United KingdomHQ checked Sep 27, 202611-5022 contacts →

Indirect evidence

“Our Chartered Security Professionals seamlessly integrate discreet and effective security into lifestyles and organisations.”

Source: RevenueBase Database · checked Sep 27, 2026
19Indirect evidenceCheltenham, United KingdomHQ checked Sep 27, 202611-5021 contacts →

Indirect evidence

“Blacksmiths is a security risk consultancy company specialising in managing Insider risk, Threats and Cyber Security.”

Source: RevenueBase Database · checked Sep 27, 2026
20Indirect evidenceLondon, United KingdomHQ checked Sep 27, 202611-5021 contacts →

Indirect evidence

“Conflict International is a London based private detective agency that offers private Investigation & Intelligence services across the UK, as well as in Europe and across the…”

Source: RevenueBase Database · checked Sep 27, 2026
21Partial evidenceLondon, United KingdomHQ checked Sep 27, 202611-5021 contacts →

Partial evidence

“AnotherDay is a new kind of defence & security consulting firm established to bring the power of effective intelligence and strategy to the challenge of safeguarding individuals…”

Source: RevenueBase Database · checked Sep 27, 2026
22Indirect evidenceLondon, United KingdomHQ checked Sep 27, 202611-5020 contacts →

Indirect evidence

“LMS Security are a fully Independent, privately owned, Internationally recognised and accredited Security Consultancy; owned and built by Electronic and Physical Security…”

Source: RevenueBase Database · checked Sep 27, 2026
23Indirect evidenceLong Bennington, United KingdomHQ checked Sep 27, 202611-5020 contacts →

Indirect evidence

“EWS is a unique global consultancy unlike any other.”

Source: RevenueBase Database · checked Sep 27, 2026
24Indirect evidenceTunbridge Wells, United KingdomHQ checked Sep 27, 202611-5019 contacts →

Indirect evidence

“Razorthorn Security is a specialist cybersecurity consultancy founded in 2007, with nearly two decades of experience helping organisations protect their data, their systems and…”

Source: RevenueBase Database · checked Sep 27, 2026
25Indirect evidenceLondon, United KingdomHQ checked Sep 27, 202611-5019 contacts →

Indirect evidence

“Our continued vision is to be the playmaker in our field; an investigation and protection consultancy, recognised for our diligence, excellence & integrity.”

Source: RevenueBase Database · checked Sep 27, 2026

Showing 25 of 327 counterintelligence consulting firms based in the United Kingdom

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Counterintelligence consulting firms based in the United Kingdom at a glance

As of Sep 27, 2026
38.3%Verified-email coverage
9.4Average contacts per company
1-10Median size (employees)
49.5%Largest-city concentration · London
Sep 27, 2026Page data refreshed

Companies by employee count

1-10
209
11-50
85
51-200
27
201-500
5
5,001-10,000
1

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 327 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 counterintelligence consulting firms, 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 “counterintelligence consulting firms”. 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 counterintelligence consulting firms), 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 counterintelligence consulting firms, 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, 1,181 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 27, 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.

Counterintelligence consulting firms by metro

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 counterintelligence consulting firms, 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 counterintelligence consulting firms are there based in the United Kingdom?

RevenueBase identified 327 counterintelligence consulting firms 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?

S-Rm, headquartered in London, tops this list with the largest team on record.

Which city has the most counterintelligence consulting firms?

London leads with 162 headquartered companies, followed by Manchester (5) and Edinburgh (4).

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 1,181 verified decision-maker contacts tracked across these 327 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 27, 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.