Company lists · Data refreshed September 2026
Top 25 Member-based business organizations based in the United Kingdom
RevenueBase identified 149 member-based business organizations headquartered in the United Kingdom as of September 2026 and tracks 672 professional contacts across them, including 93 with verified work emails. London is the largest hub.
This list covers member-based business 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.
The 25 largest member-based business organizations based in the United Kingdom
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 70 contacts → | ||||
Indirect evidence “At BITA (Business International Trading Alliance), we are the people who know people that help people.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 2 | 33 contacts → | ||||
Strong evidence “The International Advertising Association brings together over members from advertisers, agencies and media owners in over 76 countries, who rely on the IAA to keep them informed…” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 3 | 26 contacts → | ||||
Strong evidence “The MemberWise Network the leading independent and free to join professional network of membership and association professionals dedicated to promoting good practice and…” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 4 | 21 contacts → | ||||
Indirect evidence “Gatwick Diamond Business has been at the very centre of the Gatwick Diamond business community for over 70 years.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 5 | 15 contacts → | ||||
Strong evidence “Cambridge Network is a not-for-profit membership organisation for people to share ideas, collaborate and partner for shared success.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 6 | 9 contacts → | ||||
Strong evidence “Perthshire Chamber of Commerce (PCC) is an independent, non-profit making, non-political business membership organisation.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 7 | 8 contacts → | ||||
Indirect evidence “Now, more than ever, business people need to network to stay in business.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 8 | 7 contacts → | ||||
Strong evidence “Memcom brings senior leaders in the membership sector to network, collaborate and learn.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 9 | 7 contacts → | ||||
Indirect evidence “The Business Growth Network is not your run-of-the-mill business platform; it's a hub where innovative minds converge to amplify their growth potential.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 10 | 6 contacts → | ||||
Strong evidence “Advantia is a not-for-profit dealer group run for the sole purpose of enabling our members to be highly competitive and highly profitable.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 11 | 6 contacts → | ||||
Strong evidence “Our members are business professionals who help each other grow their businesses through their commitment to our principal core value, Givers Gain®.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 12 | 5 contacts → | ||||
Indirect evidence “Gaining Together: The concept is simple - our collaborative networkers benefit financially from any referrals they share between them.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 13 | 5 contacts → | ||||
Indirect evidence “Revitalise Business Club (RBC) is more than just networking, It’s a community designed to help entrepreneurs, business owners, and professionals build genuine connections…” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 14 | 4 contacts → | ||||
Strong evidence “The RDLC is the biggest and fastest-growing recruitment membership club.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 15 | 4 contacts → | ||||
Indirect evidence “The Business Buyers Club was founded by Guy Bartlett, the UK's leading expert in company acquisitions.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 16 | 4 contacts → | ||||
Indirect evidence “Business networking is about so much more than making sales.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 17 | 4 contacts → | ||||
Strong evidence “We Are Wakefield is a membership organisation for businesses to network, collaborate and support each other to succeed and thrive.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 18 | 3 contacts → | ||||
Indirect evidence “Whether providing face-to-face lunchtime networking events, as we have been since 1993, or hosting our more recent and equally successful online events, our purpose remains the…” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 19 | 3 contacts → | ||||
Indirect evidence “Where do you get most of your business?” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 20 | 3 contacts → | ||||
Strong evidence “In BNI our South Wales-based members enjoy unparalleled business growth.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 21 | 2 contacts → | ||||
Indirect evidence “Who are Collaborate MK?” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 22 | 2 contacts → | ||||
Strong evidence “Societas is an Exclusive Member-only organisation for Owners, Directors and CEOs of medium to large enterprises.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 23 | 2 contacts → | ||||
Indirect evidence “The BNC is an association for event professionals that has been successfully bringing together ideas, initiatives and – most importantly – people since 1997.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 24 | 2 contacts → | ||||
Strong evidence “Darlington Business Club membership organisation to provide opportunities to network and build relationships in our local area.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 25 | 2 contacts → | ||||
Indirect evidence “BNI provides a positive, supportive, and structured environment for the development and exchange of quality business referrals.” Source: RevenueBase Database · checked Sep 20, 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: member-based business 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 member-based business organizations.
- Partial evidence
- Its own public description names part of member-based business organizations, so it works in or next to the category without describing itself that way.
- Indirect evidence
- The description shown does not name member-based business 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 149 member-based business organizations based in the United Kingdom
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Member-based business organizations based in the United Kingdom at a glance
As of Sep 20, 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 149 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 member-based business 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 “member-based business 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 member-based business 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 member-based business 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, 93 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.
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 member-based business 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 member-based business organizations are there based in the United Kingdom?
RevenueBase identified 149 member-based business 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?
BITA, headquartered in Maidstone, tops this list with the largest team on record.
Which city has the most member-based business organizations?
London leads with 23 headquartered companies, followed by Birmingham (4) and Glasgow (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 93 verified decision-maker contacts tracked across these 149 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.
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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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