Posted by: Adam Weston
19 January 2024
Understanding the role of membership bodies and why digital matters
Last updated: July 2025 with latest membership data.
Membership bodies provide essential support, representation and professional resources to millions across the UK. From industry regulators to member-led associations, these organisations connect individuals and businesses through knowledge sharing, networking and professional development.
But while their purpose is constant, member expectations are not. Members want more than newsletters and renewals. They expect modern features like natural-language search, personalised content and services that help them grow both professionally and personally.
So, what does this mean for membership bodies?
As expectations rise and to stay relevant and meet member demands, organisations need scalable platforms that enhance engagement, streamline processes and reduce administrative overheads. Growcreate is here to help membership bodies navigate this transformation.
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 and knowledge sharing, these bodies empower their members to improve 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.
The powerhouses of UK membership
Membership bodies wield significant influence over their respective industries. As the collective voice of their members, these organisations advocate for their interests and provide unwavering support. The NUS, English Heritage, and the Caravan and Motorhome Club are among the giants that drive progress across the sector.
Whether through trade associations or professional bodies, membership organisations play a key role in advocating for their industries and establishing standards of competence and ethics.
How can membership bodies leverage digital solutions to increase their impact?
Growcreate helps membership organisations reduce admin, enhance member engagement and achieve measurable growth. Our scalable platforms provide a seamless integration of systems, delivering a smooth user experience for both administrators and members. With Azure hosting and continuous support, we help your digital transformation initiatives stay on track and drive long-term success.
Why membership data needs a health warning
Across the UK’s top 100 membership bodies, official data is often flimsy, anecdotal, or outdated which calls into question its reliability. Many organisations don’t regularly publish actual member numbers, instead relying on vague terms like “over x,000” or occasional figures pulled from dated annual reports. Even government evaluations of digital maturity note that “this data represented is not consistently tracked and managed”.
Likewise, mainstream estimates tend to repeat the same rounded totals, with limited independent verification. As such, these numbers serve more as directional indicators which is useful for spotting trends, but not for drawing precise conclusions without direct validation.
Top 100 membership bodies in the UK
Below is the comprehensive list of the UK’s top 100 membership bodies, ranked by membership numbers for 2024 and 2025. These are the influential organisations leading the way in their respective sectors.
| Rank 2024 | Rank 2025 | Membership bodies | 2024 Members | 2025 Members | Change |
| 1 | 1 | National Union of Students (NUS) | 7,000,000 | 7,000,000 | 0 |
| 2 | 2 | Trades Union Congress (TUC) | 5,500,000 | 5,500,000 | 0 |
| 3 | 3 | National Trust | 5,370,000 | 5,380,000 | 10,000 |
| 6 | 4 | Unison | 1,300,000 | 1,300,000 | 0 |
| 4 | 5 | English Heritage | 1,700,000 | 1,200,000 | -500,000 |
| 5 | 6 | Unite | 1,400,000 | 1,200,000 | -200,000 |
| 7 | 7 | Royal Society for the Protection of Birds (RSPB) | 1,200,000 | 1,200,000 | 0 |
| 8 | 8 | Caravan and Motorhome Club | 1,100,000 | 1,000,000 | -100,000 |
| 9 | 9 | Wildlife Trusts | 900,000 | 900,000 | 0 |
| 10 | 10 | England Golf | 737,000 | 737,000 | 0 |
| 11 | 11 | Camping and Caravanning Club | 700,000 | 700,000 | 0 |
| 12 | 12 | Royal Horticultural Society (RHS) | 600,000 | 600,000 | 0 |
| 14 | 13 | The Scout Association | 547,000 | 547,000 | 0 |
| 13 | 14 | GMB | 570,000 | 500,000 | -70,000 |
| 15 | 15 | Royal College of Nursing (RCN) | 500,000 | 500,000 | 0 |
| 16 | 16 | Woodland Trust | 500,000 | 500,000 | 0 |
| 17 | 17 | National Education Union | 445,000 | 497,400 | 52,400 |
| 23 | 18 | British Gymnastics | 400,000 | 400,000 | 0 |
| 18 | 19 | University of the Third Age (u3a) | 430,000 | 400,000 | -30,000 |
| 20 | 20 | Girlguiding UK | 370,000 | 370,000 | 0 |
| 22 | 21 | Union of Shop Distributive and Allied Workers (USDAW) | 360,000 | 360,000 | 0 |
| 21 | 22 | Oddfellows | 369,000 | 344,000 | -25,000 |
| 24 | 23 | National Trust for Scotland | 300,000 | 330,000 | 30,000 |
| 19 | 24 | Labour Party | 395,000 | 309,000 | -86,000 |
| 25 | 25 | NASUWT | 300,000 | 300,000 | 0 |
| 26 | 26 | Association of Chartered Certified Accountants (ACCA) | 241,000 | 252,500 | 11,500 |
| 27 | Reform UK | 227,644 | 227,644 | ||
| 27 | 28 | Law Society of England and Wales (TLS) | 200,000 | 200,000 | 0 |
| 28 | 29 | Historic Environment Scotland | 200,000 | 195,000 | -5,000 |
| 34 | 30 | Public and Commercial Services Union (PCS) | 183,000 | 191,289 | 8,289 |
| 31 | 31 | British Medical Association (BMA) | 190,366 | 190,366 | 0 |
| 29 | 32 | Wildfowl and Wetlands Trust | 200,000 | 185,000 | -15,000 |
| 33 | 33 | Communication Workers Union (CWU) | 185,000 | 185,000 | 0 |
| 32 | 34 | Women’s Institute (WI) | 190,000 | 180,000 | -10,000 |
| 35 | 35 | Royal British Legion (RBL) | 180,000 | 180,000 | 0 |
| 37 | 36 | Wine Society | 180,000 | 180,000 | 0 |
| 30 | 37 | Institute of Chartered Accountants of England and Wales (ICAEW) | 198,500 | 172,273 | -26,227 |
| 39 | 38 | United Grand Lodge of England | 175,000 | 170,000 | -5,000 |
| 48 | 39 | Chester Zoo | 165,000 | 165,000 | 0 |
| 42 | 40 | Chartered Institute of Personnel and Development (CIPD) | 160,000 | 160,000 | 0 |
| 43 | 41 | Prospect (Union) | 157,000 | 157,000 | 0 |
| 44 | 42 | Institution of Engineering and Technology (The IET) | 154,000 | 156,000 | 2,000 |
| 45 | 43 | British Association for Shooting and Conservation (BASC) | 150,000 | 150,000 | 0 |
| 36 | 44 | Chartered Management Institute (CMI) | 180,000 | 150,000 | -30,000 |
| 38 | 45 | Campaign for Real Ale (CAMRA)s | 136,645 | 150,000 | 13,355 |
| 41 | 46 | Boundless (CSMA) | 165,000 | 150,000 | -15,000 |
| 52 | 47 | England and Great Britain Hockey | 140,000 | 146,000 | 6,000 |
| 47 | 48 | Police Federation of England and Wales | 145,000 | 145,000 | 0 |
| 54 | 49 | Royal Institution of Chartered Surveyors (RICS) | 134,000 | 144,000 | 10,000 |
| 49 | 50 | England Athletics | 142,000 | 142,000 | 0 |
| 50 | 51 | Tate Museum | 142,000 | 142,000 | 0 |
| 51 | 52 | Civil Service Sports Council (CSSC) | 140,000 | 140,000 | 0 |
| 53 | 53 | Art Fund | 135,000 | 135,000 | 0 |
| 40 | 54 | Conservative Party | 172,000 | 131,680 | -40,320 |
| 46 | 55 | British Cycling | 145,000 | 130,000 | -15,000 |
| 55 | 56 | Youth Hostels Association (England and Wales) | 130,000 | 130,000 | 0 |
| 56 | 57 | Association of Accounting Technicians (AAT) | 124,000 | 124,000 | 0 |
| 57 | 58 | Chartered Insurance Institute (CII) | 122,000 | 122,000 | 0 |
| 58 | 59 | University and College Union (UCU) | 120,000 | 120,000 | 0 |
| 59 | 60 | British Horse Society (BHS) | 120,000 | 120,000 | 0 |
| 63 | 61 | All England Netball | 100,000 | 117,000 | 17,000 |
| 60 | 62 | Institution of Mechanical Engineers (IMechE) | 115,000 | 115,000 | 0 |
| 61 | 63 | Kew Gardens and Wakehurst | 104,875 | 104,875 | 0 |
| 64 | 64 | Royal Yachting Association (RYA) | 100,000 | 100,000 | 0 |
| 65 | 65 | Ramblers | 100,000 | 100,000 | 0 |
| 66 | 66 | Countryside Alliance | 100,000 | 100,000 | 0 |
| 67 | 67 | National Residential Landlords Association (NRLA) | 100,000 | 100,000 | 0 |
| 68 | 68 | World Wildlife Fund (WWF) | 100,000 | 100,000 | 0 |
| 70 | 69 | Institute of the Motor Industry (IMI) | 94,000 | 110,000 | 16,000 |
| 78 | 70 | Spotlight | 70,000 | 95,000 | 25,000 |
| 69 | 71 | Institution of Civil Engineers (ICE) | 95,000 | 92,000 | -3,000 |
| 71 | 72 | Arts Society (NADFAS) | 90,000 | 90,000 | 0 |
| 75 | 73 | Liberal Democrats | 74,000 | 90,000 | 16,000 |
| 72 | 74 | British Canoeing | 87,000 | 87,000 | 0 |
| 73 | 75 | British Mountaineering Council | 80,163 | 80,163 | 0 |
| 74 | 76 | National Governance Association | 80,000 | 80,000 | 0 |
| 79 | 77 | Royal Air Forces Association | 67,000 | 79,000 | 12,000 |
| 78 | Paddle UK | 75,000 | 75,000 | ||
| 79 | IAM RoadSmart | 100,000 | 100,000 | ||
| 76 | 80 | MotorSport UK | 70,000 | 70,000 | 0 |
| 81 | Cycling UK | 70,000 | 70,000 | 0 | |
| 83 | 82 | Historic Houses | 70,000 | 70,000 | 0 |
| 77 | 83 | British Computer Society (BCS) | 70,000 | 70,000 | 0 |
| 80 | 84 | Chartered Society of Physiotherapy (CSP) | 65,000 | 65,000 | 0 |
| 81 | 85 | Coeliac UK | 65,000 | 65,000 | 0 |
| 62 | 86 | Scottish National Party | 104,000 | 64,525 | -39,475 |
| 82 | 87 | Chartered Institute of Procurement and Supply (CIPS) | 64,000 | 64,000 | 0 |
| 84 | 88 | Educational Institute of Scotland | 56,342 | 56,342 | 0 |
| 85 | 89 | Green Party | 54,000 | 54,000 | 0 |
| 86 | 90 | Royal College of General Practitioners (RCGP) | 54,000 | 54,000 | 0 |
| 87 | 91 | English Bridge Union | 54,000 | 54,000 | 0 |
| 88 | 92 | British Psychological Society (BPS) | 50,000 | 50,000 | 0 |
| 89 | 93 | British Association for Counselling and Psychotherapy (BACP) | 50,000 | 50,000 | 0 |
| 90 | 94 | Royal Society of Chemistry (RSC) | 50,000 | 50,000 | 0 |
| 91 | 95 | Royal College of Midwives | 50,000 | 50,000 | 0 |
| 92 | 96 | Crohn’s & Colitis UK | 50,000 | 50,000 | 0 |
| 93 | 97 | Chartered Institute of Building (CIOB) | 50,000 | 50,000 | 0 |
| 94 | 98 | NEDonBoard | 47,300 | 47,300 | 0 |
| 95 | 99 | Equity | 47,000 | 47,000 | 0 |
| 96 | 100 | CADW | 44,100 | 44,100 | 0 |
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.
The role of membership bodies is empowering it's members
Membership bodies support their members by offering various benefits and services for professional growth, like 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 is the result of extensive research and analysis.
Scalable membership platforms for long-term growth
Growcreate helps membership bodies and nonprofits streamline processes, reduce operational overhead and deliver engaging, personalised experiences for members. Through platform development and 24/7 support, we ensure your digital systems remain secure, scalable and efficient.
Want to take your membership platform to the next level?
We specialise in providing digital solutions that simplify administration and improve member engagement. From custom web development to cloud hosting on Azure, we can help you scale while keeping operational costs under control.
Unveiling the source
The UK’s Top 100 List of Membership Bodies is based on extensive research and data, derived from a variety of sources, including annual reports, online directories and direct contributions from membership bodies themselves. The goal is to provide a reliable resource for individuals and businesses seeking to connect with the UK’s leading membership organisations.
Is your organisation in the top 100?
If your membership organisation is listed above and you believe your numbers are outdated or need correction, feel free to reach out with updated information. We are committed to providing the most accurate and current data.
How Growcreate supports membership bodies
As a digital solutions agency with a focus on long-term partnerships, Growcreate is the ideal partner for membership organisations looking to enhance their digital presence. We specialise in:
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Custom website development: Scalable, high-performance websites that adapt as your organisation grows.
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24/7 support: Ongoing support to ensure your platforms run smoothly at all times.
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Cloud hosting: Secure, reliable Azure hosting solutions for high-traffic membership platforms.
We help membership bodies stay ahead by ensuring their digital platforms are future-proof and aligned with evolving member expectations.
Are you ready to drive your membership body’s digital transformation?
Contact Growcreate today for a free consultation or to explore how we can help improve your platform’s scalability, security, and member engagement.
Next steps for membership bodies
We understand that digital transformation can feel overwhelming. That's why we’re here to guide membership bodies through every step of the process. Whether you’re looking to improve member engagement, streamline operations or scale your platform, Growcreate offers the expertise and tools you need to succeed.
Reach out today and let’s start the conversation about how Growcreate can help your organisation grow and thrive.
Membership Body FAQs
A membership body or professional body is an organisation that brings together individuals or businesses within a specific industry, profession or interest group. These bodies provide resources and support for professional development, networking, and advocacy.
Key features of membership bodies include:
Membership-based
Individuals or businesses join voluntarily to access benefits such as training, certifications, and industry resources.
Professional development
They offer training, certifications, and events to help members grow in their careers.
Advocacy and representation
Professional bodies represent their members' interests to governments, regulators, and other industry stakeholders.
Networking opportunities
They connect members to foster knowledge sharing and business opportunities.
Industry standards
Many set and enforce professional standards, codes of ethics, and best practices within their field.
Growcreate specialises in enhancing the performance of membership platforms by identifying and resolving performance bottlenecks. We optimise site speed, user experience and overall functionality, ensuring your platform runs smoothly even as your membership base grows.
Growcreate boosts member engagement and retention by creating personalised, seamless experiences. We integrate AI-powered search, intuitive navigation and relevant content, ensuring that members can easily access what they need and stay engaged with your platform.
We prioritise security and reliability by using Microsoft Azure Cloud hosting, implementing strong data encryption, multi-factor authentication and continuous monitoring. Our 24/7 support ensures your platform remains secure and performs reliably, protecting both your organisation and your members.
Growcreate helps your platform scale by leveraging cloud-based infrastructure and custom solutions designed to handle increased traffic and growing member numbers. We ensure your platform adapts seamlessly to new features, larger data volumes and evolving user needs without compromising performance.
Growcreate is the ideal partner for optimising your membership platform because of our expertise in Umbraco, Azure and cloud-based solutions. We focus on long-term partnerships, delivering tailored solutions that streamline operations, enhance security and improve member engagement, ensuring your platform’s continuous success.
