UK’s Top 100 List of Membership Bodies 2024

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Membership bodies provide crucial support, representation, and resources to their members. These organisations form a diverse landscape of membership associations, each catering to different professions, trades, and interests. These bodies serve as invaluable networks for professionals, businesses, and individuals alike, fostering connections and facilitating growth.

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In this article, we will look at the role of membership bodies and provide a list of the top 100 membership bodies in the UK based on membership.

By offering a platform for collaboration, knowledge sharing, and resource access, these bodies empower their members to enhance their professional development and achieve their objectives. 

Understanding Membership Bodies

A membership body is an organisation that brings together individuals or businesses with shared interests, professions, or goals. By offering a platform for collaboration, knowledge sharing, and resource access, these bodies empower their members to enhance their professional development and achieve their objectives. Whether they take the form of trade associations, industry organisations, or professional bodies, membership organisations play a vital role in uniting like-minded individuals and fostering collective progress.


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The Powerhouses of UK Membership

Within the United Kingdom, membership bodies wield significant influence over their respective industries. As the collective voice of their members, these organisations tirelessly advocate for their interests and provide unwavering support. The NUS, English Heritage, and the Caravan and Motorhome Club are among the notable giants in the UK's membership landscape.

Trade associations, featured in the UK Trade Association Directory, occupy a critical position within specific sectors. Trade associations foster collaboration, knowledge exchange, and policy advocacy by effectively representing the interests of businesses and professionals operating within their industries.

Meanwhile, professional bodies in the UK focus on specific professions or disciplines. They establish industry standards, offer certifications, and provide ongoing professional development opportunities. These bodies play a crucial role in upholding high standards of competence and ethics across various fields.

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Unveiling Prominent Membership Bodies

Here are the top 100 membership bodies in the UK:

2024 Rank Membership Organisation 2024 Members
1 National Union of Students (NUS) 7,000,000
2 Trades Union Congress (TUC) 5,500,000
3 National Trust 5,370,000
4 English Heritage 1,700,000
5 Unite 1,400,000
6 Unison 1,300,000
7 Royal Society for the Protection of Birds (RSPB) 1,200,000
8 Caravan and Motorhome Club 1,100,000
9 Wildlife Trusts 900,000
10 England Golf 737,000
11 Camping and Caravanning Club 700,000
12 Royal Horticultural Society (RHS) 600,000
13 GMB 570,000
14 The Scout Association 547,000
15 Royal College of Nursing (RCN) 500,000
16 Woodland Trust 500,000
17 National Education Union 445,000
18 University of the Third Age 430,000
19 Labour Party 395,000
20 Girlguiding UK 370,000
21 Oddfellows 369,000
22 Union of Shop Distributive and Allied Workers (USDAW) 360,000
23 British Gymnastics 350,000
24 National Trust for Scotland 300,000
25 NASUWT 300,000
26 Association of Chartered Certified Accountants (ACCA) 241,000
27 Law Society of England and Wales (TLS) 200,000
28 Historic Environment Scotland 200,000
29 Wildfowl and Wetlands Trust 200,000
30 Institute of Chartered Accountants of England and Wales (ICAEW) 198,500
31 British Medical Association (BMA) 190,366
32 Women’s Institute (WI) 190,000
33 Communication Workers Union (CWU) 185,000
34 Public and Commercial Services Union (PCS) 183,000
35 Royal British Legion (RBL) 180,000
36 Chartered Management Institute (CMI) 180,000
37 Wine Society 180,000
38 Campaign for Real Ale (CAMRA)s 180,000
39 United Grand Lodge of England 175,000
40 Conservative Party 172,000
41 Boundless (CSMA) 165,000
42 Chartered Institute of Personnel and Development (CIPD) 160,000
43 Prospect (Union) 157,000
44 Institution of Engineering and Technology (The IET) 154,000
45 British Association for Shooting and Conservation (BASC) 150,000
46 British Cycling 145,000
47 Police Federation of England and Wales 145,000
48 Chester Zoo 145,000
49 England Athletics 142,000
50 Tate Museum 142,000
51 Civil Service Sports Council (CSSC) 140,000
52 England and Great Britain Hockey 140,000
53 Art Fund 135,000
54 Royal Institution of Chartered Surveyors (RICS) 134,000
55 Youth Hostels Association (England and Wales) 130,000
56 Association of Accounting Technicians (AAT) 124,000
57 Chartered Insurance Institute (CII) 122,000
58 University and College Union (UCU) 120,000
59 British Horse Society (BHS) 120,000
60 Institution of Mechanical Engineers (IMechE) 115,000
61 Kew Gardens and Wakehurst 104,875
62 Scottish National Party 104,000
63 All England Netball 100,000
64 Royal Yachting Association (RYA) 100,000
65 Ramblers 100,000
66 Countryside Alliance 100,000
67 National Residential Landlords Association (NRLA) 100,000
68 World Wildlife Fund (WWF) 100,000
69 Institution of Civil Engineers (ICE) 95,000
70 Institute of the Motor Industry (IMI) 94,000
71 Arts Society (NADFAS) 90,000
72 British Canoeing 87,000
73 British Mountaineering Council 82,000
74 National Governance Association 80,000
75 Liberal Democrats 74,000
76 MotorSport Uk 70,000
77 British Computer Society (BCS) 70,000
78 Spotlight 70,000
79 Royal Air Forces Association 67,000
80 Chartered Society of Physiotherapy (CSP) 65,000
81 Coeliac UK 65,000
82 Chartered Institute of Procurement and Supply (CIPS) 64,000
83 Historic Houses 60,000
84 Educational Institute of Scotland 56,342
85 Green Party 54,000
86 Royal College of General Practitioners (RCGP) 54,000
87 English Bridge Union 54,000
88 British Psychological Society (BPS) 50,000
89 British Association for Counselling and Psychotherapy (BACP) 50,000
90 Royal Society of Chemistry (RSC) 50,000
91 Royal College of Midwives 50,000
92 Crohn’s & Colitis UK 50,000
93 Chartered Institute of Building (CIOB) 50,000
94 NEDonBoard 47,300
95 Equity 47,000
96 CADW 44,100
97 Institution of Occupational Safety and Health (IOSH) 44,000
98 Royal Institute of British Architects (RIBA) 28,000
99 Who are you? Get in touch if you think you rank. -
100 Who are you? Get in touch if you think you rank. -
Please note that this list is not exhaustive, as the UK boasts a vast array of membership bodies that cater to diverse industries and professions.

Empowering Members: The Role of Membership Bodies

Membership bodies assume a pivotal role in supporting their members, offering various benefits and services to foster professional growth, facilitating networking opportunities, and granting access to valuable resources. Some common responsibilities of membership bodies include:

  • Championing the interests of members on a national or industry level
  • Providing industry-specific research, insights, and market intelligence
  • Organising events, conferences, and seminars to foster networking and knowledge-sharing
  • Offering professional development programs, certifications, and training initiatives
  • Facilitating collaboration and partnerships within the industry
  • Granting access to resources, best practices, and industry-specific publications

Membership bodies act as a united force, pooling professionals' and businesses' expertise and collective efforts to drive industry growth, innovation, and success.

The UK’s Top 100 List of Membership Bodies 2024 is the result of extensive research and analysis.

Unveiling the Source

The UK’s Top 100 List of Membership Bodies 2024 is derived from various sources, including annual reports, online directories, and membership organisation's websites. This list aims to showcase the membership bodies across various sectors in the UK based on member numbers.

If your organisation ranks in the top 100 get in touch

You'll find a link to the source in the table. If your membership organisation has more or fewer members than stated on this page, contact and provide the relevant link with the updated data. We'll happily change the information to provide the most accurate information available.

That said, many organisations are rounding up their quoted numbers or haven't updated them recently, and it would be great to have more accurate figures for 2024.

Our objective in compiling this list is to provide a valuable resource for individuals and businesses seeking to connect with relevant membership bodies and leverage their benefits.

For more information about membership bodies in the UK, please visit the respective websites of the organisations mentioned in this post.