Company lists · Data refreshed September 2026

Top 25 Investigative site organizations based in the United Kingdom

Name: Investigative site organizations based in the United Kingdom
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 20, 2026 167 companies tracked

RevenueBase identified 167 investigative site organizations headquartered in the United Kingdom as of September 2026 and tracks 5,880 professional contacts across them, including 2,571 with verified work emails. London is the largest hub.

This list covers investigative site organizations 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 20, 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 20, 2026 86% judged on-target in blind review

167Companies

5,880Contacts tracked

2,571Verified emails

Explore this list → Free signup · no credit card · 500 free credits

The 25 largest investigative site organizations based in the United Kingdom

Ranked by team size

Top 25 of 167 investigative site organizations based in the United Kingdom, ranked by team size, largest first. Data refreshed Sep 20, 2026. RevenueBase Smart Search rates how each company's information relates to investigative site organizations: 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	Perceptive INC	Indirect evidence	London, United KingdomHQ checked Sep 20, 2026	1,001-5,000	1,197 contacts →
	Indirect evidence “Expanding on their combined 50-year history, Perceptive provides best-in-class specialist support to global pharmaceutical, biotech, and clinical research organizations, spanning…” Source: RevenueBase Database · checked Sep 20, 2026
2	MAC Clinical Research	Indirect evidence	Blackpool, United KingdomHQ checked Sep 20, 2026	201-500	333 contacts →
	Indirect evidence “MAC Clinical Research is a leading full-service, global Contract Research Organisation (CRO) with over 30 years of experience in clinical trial management.” Source: RevenueBase Database · checked Sep 20, 2026
3	WEP Clinical	Indirect evidence	London, United KingdomHQ checked Sep 20, 2026	201-500	321 contacts →
	Indirect evidence “At WEP Clinical, we operate as a specialist CRO with a proven track record of excellence in designing, managing, and executing Clinical Trials, Expanded Access Programs (EAPs)…” Source: RevenueBase Database · checked Sep 20, 2026
4	Futuremeds	Partial evidence	Liverpool, United KingdomHQ checked Sep 20, 2026	501-1,000	282 contacts →
	Partial evidence “FutureMeds is an independent, fully-owned European Site Network and DCT service provider dedicated to running patient-centric clinical trials and delivering quality data for the…” Source: RevenueBase Database · checked Sep 20, 2026
5	HVIVO	Indirect evidence	London, United KingdomHQ checked Sep 20, 2026	51-200	214 contacts →
	Indirect evidence “hVIVO plc (Ticker: HVO) is a science‑led early‑phase drug development company purpose‑built to meet the growing complexity of modern clinical research.” Source: RevenueBase Database · checked Sep 20, 2026
6	Illingworth Research Group A Syneos Health Company	Indirect evidence	Macclesfield, United KingdomHQ checked Sep 20, 2026	51-200	208 contacts →
	Indirect evidence “Illingworth Research Group™, a Syneos Health® company, is a leading provider of clinical research home health services, providing highly trained, qualified and experienced…” Source: RevenueBase Database · checked Sep 20, 2026
7	Richmond Pharmacology	Indirect evidence	London, United KingdomHQ checked Sep 20, 2026	51-200	198 contacts →
	Indirect evidence “At Richmond, we're on a mission to transform healthcare by delivering faster answers and turning hope into tangible solutions.” Source: RevenueBase Database · checked Sep 20, 2026
8	Quanticate	Indirect evidence	Hitchin, United KingdomHQ checked Sep 20, 2026	201-500	192 contacts →
	Indirect evidence “Quanticate is a leading global data focused clinical research organisation (CRO) primarily focused on the management, analysis and reporting of data from clinical trials and…” Source: RevenueBase Database · checked Sep 20, 2026
9	Clintec	Indirect evidence	Glasgow, United KingdomHQ checked Sep 20, 2026	501-1,000	136 contacts →
	Indirect evidence “Clintec, an IQVIA company, is an innovative, medium-sized, global Contract Research Organization providing global full and functional service support to the pharmaceutical…” Source: RevenueBase Database · checked Sep 20, 2026
10	Panthera Biopartners	Indirect evidence	Preston, United KingdomHQ checked Sep 20, 2026	11-50	127 contacts →
	Indirect evidence “Panthera is an independent SMO working with pharmaceutical and contract research organizations to find the right patient, for the right trial, at the right time through the…” Source: RevenueBase Database · checked Sep 20, 2026
11	Transpharmation LTD	Indirect evidence	London, United KingdomHQ checked Sep 20, 2026	51-200	119 contacts →
	Indirect evidence “Transpharmation is a contract research organisation led by scientists.” Source: RevenueBase Database · checked Sep 20, 2026
12	Medicines Evaluation Unit Ltd, An Iqvia Business	Indirect evidence	Manchester, United KingdomHQ checked Sep 20, 2026	51-200	97 contacts →
	Indirect evidence “The Medicines Evaluation Unit (MEU) Ltd, an IQVIA business, is one of the UK’s leading contract research organisations, a facility where commitment to excellence is paramount.” Source: RevenueBase Database · checked Sep 20, 2026
13	Innovative Trials	Indirect evidence	Letchworth Garden City, United KingdomHQ checked Sep 20, 2026	51-200	95 contacts →
	Indirect evidence “Innovative Trials was built around a simple belief, patient recruitment works better when people feel supported.” Source: RevenueBase Database · checked Sep 20, 2026
14	TMLEP	Indirect evidence	Ashford, United KingdomHQ checked Sep 20, 2026	11-50	94 contacts →
	Indirect evidence “Providing independent medical expert evidence to insurers, healthcare providers, law firms, regulators, and public bodies to help resolve complex clinical negligence claims.” Source: RevenueBase Database · checked Sep 20, 2026
15	IXICO	Indirect evidence	London, United KingdomHQ checked Sep 20, 2026	51-200	92 contacts →
	Indirect evidence “IXICO is no ordinary Imaging Contract Research Organisation (iCRO).” Source: RevenueBase Database · checked Sep 20, 2026
16	Dunelm Geotechnical & Environmental LTD	Strong evidence	Durham, United KingdomHQ checked Sep 20, 2026	51-200	77 contacts →
	Strong evidence “Dunelm has 50 years’ experience as leaders in the field of ground investigation, providing site investigation services on a national scale at competitive prices.” Source: RevenueBase Database · checked Sep 20, 2026
17	Oxon Epidemiology	Indirect evidence	London, United KingdomHQ checked Sep 20, 2026	51-200	60 contacts →
	Indirect evidence “OXON Epidemiology is a European full-service Contract Research Organization (CRO) specialised in real-world evidence (RWE) and observational research across all major therapeutic…” Source: RevenueBase Database · checked Sep 20, 2026
18	Examworks Investigation Services	Partial evidence	Bolton, United KingdomHQ checked Sep 20, 2026	51-200	51 contacts →
	Partial evidence “ExamWorks Investigation Services is a leading claims investigation company providing the insurance, banking, retail and other sectors with a range of innovative and cost effective…” Source: RevenueBase Database · checked Sep 20, 2026
19	ARC Regulatory	Indirect evidence	Belfast, United KingdomHQ checked Sep 20, 2026	11-50	42 contacts →
	Indirect evidence “ARC's purpose is to expedite access to precision medicine clinical trials for patients globally.” Source: RevenueBase Database · checked Sep 20, 2026
20	PVR People. Value. Research	Indirect evidence	Ipswich, United KingdomHQ checked Sep 20, 2026	51-200	35 contacts →
	Indirect evidence “End-to-end CRO services Strategic consultation for all aspects of your trial Customizing an optimal trial design Fit-for-purpose data End-to-end patient focused services Quick…” Source: RevenueBase Database · checked Sep 20, 2026
21	Histologix	Indirect evidence	Nottingham, United KingdomHQ checked Sep 20, 2026	11-50	34 contacts →
	Indirect evidence “A trusted GLP & GCP Compliant CRO for Tissue Based Analysis Make the most of our expertise in Histology, Immunohistochemistry (IHC), Immunofluorescence (IF), In Situ Hybridisation…” Source: RevenueBase Database · checked Sep 20, 2026
22	RGI	Partial evidence	Cheadle Hulme, United KingdomHQ checked Sep 20, 2026	51-200	30 contacts →
	Partial evidence “RGI Solutions - Solving the Toughest Cases with Precision and Expertise Welcome to RGI Solutions, the leading independent investigations company in the UK!” Source: RevenueBase Database · checked Sep 20, 2026
23	Verita	Indirect evidence	London, United KingdomHQ checked Sep 20, 2026	11-50	28 contacts →
	Indirect evidence “Verita is the leading independent consultancy for regulated organisations in the UK.” Source: RevenueBase Database · checked Sep 20, 2026
24	Clinvigilant Research	Indirect evidence	Dartford, United KingdomHQ checked Sep 20, 2026	51-200	25 contacts →
	Indirect evidence “Clinvigilant Research is a leading provider of comprehensive services to the life sciences industry, specializing in Contract Research Organization (CRO) services, eClinical…” Source: RevenueBase Database · checked Sep 20, 2026
25	Accelerating Clinical Trials LTD	Indirect evidence	Birmingham, United KingdomHQ checked Sep 20, 2026	11-50	24 contacts →
	Indirect evidence “A not-for-profit company, any surplus income is reinvested for blood cancer patients’ benefit.” Source: RevenueBase Database · checked Sep 20, 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: investigative site organizations. 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 investigative site organizations.
Partial evidence: Its own public description names part of investigative site organizations, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name investigative site organizations. 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 167 investigative site organizations based in the United Kingdom

See the full list, filter by size, metro and specialty, and get verified emails and direct dials for all 2,571 reachable decision-makers.

Free signup · no credit card

View the full list →

Investigative site organizations based in the United Kingdom at a glance

As of Sep 20, 2026

43.7%Verified-email coverage

35.2Average contacts per company

11-50Median size (employees)

29.3%Largest-city concentration · London

Sep 20, 2026Page data refreshed

Companies by employee count

1-10

11-50

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 167 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 investigative site organizations, 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 “investigative site organizations”. 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 investigative site organizations), 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 investigative site organizations, 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, 2,571 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 20, 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.

Investigative site organizations by metro

Investigative site organizations in London49

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 investigative site organizations, 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 investigative site organizations are there based in the United Kingdom?

RevenueBase identified 167 investigative site organizations 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?

Perceptive INC, headquartered in London, tops this list with the largest team on record.

Which city has the most investigative site organizations?

London leads with 49 headquartered companies, followed by Manchester (7) and Glasgow (5).

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 2,571 verified decision-maker contacts tracked across these 167 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 20, 2026.

Ready to reach these companies? Verified emails and direct dials for all 167 investigative site organizations based in the United Kingdom. Start with a free account, no credit card.

Download this list →

Related lists

Investigative site organizations by geography

Browse the directory

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.