You've probably heard the phrase a thousand times — "join the union" — without anyone actually explaining what one is. Here's the short version.
The basic definition
A trade union is an organisation of workers, formed to look after their interests at work. In the UK, the legal definition is more specific: a trade union is an organisation whose main purpose is to regulate relations between workers and employers, and which is registered with the Certification Officer (an independent regulator). That registration matters — it's what gives trade unions specific legal rights and responsibilities.
In practice, trade unions in the UK do a mix of two things: collective work (negotiating pay and conditions on behalf of all their members, campaigning, industrial action) and individual work (representing members in disputes, advising them, helping them through difficult moments at work).
What unions actually do
Most UK trade unions do some version of all of the following:
- Collective bargaining. Negotiating with employers — or, in education, with government bodies and pay review bodies — on pay, hours, workload and conditions for all their members. The biggest tangible result of this is the annual pay award teachers receive.
- Individual representation. If a member faces a disciplinary, capability, grievance, redundancy or other employment issue, the union provides a rep to support them and, if needed, legal representation.
- Policy and campaigning. Lobbying government on education policy, workload, funding, curriculum, accountability and so on. Some unions also campaign on wider social and political issues.
- Professional development and resources. Many provide CPD, classroom resources, professional networks, conferences and discounts.
- Industrial action where necessary. If negotiation fails, unions can ballot members on strike action or other forms of industrial action. UK law sets fairly strict requirements on how this has to be done.
How teaching unions are different
Teaching unions are simply trade unions whose members work in education. The main difference from a general union (like Unite or GMB) is the sector focus. A teaching union's reps, casework specialists and policy work are all built around education-sector issues — the STPCD pay framework, Ofsted, the Early Career Framework, leadership accountability, and so on.
Within UK teaching specifically, there are a few categories:
- General teaching unions — open to all classroom teachers, leaders and (in some cases) support staff. NEU and NASUWT are the two largest in England and Wales. EIS is the largest in Scotland.
- Leadership-specific unions — for senior staff only. ASCL covers secondary leaders and is independent of the TUC; NAHT covers all leadership levels and is a TUC affiliate.
- Nation-specific unions — UCAC in Wales, AHDS and SLS in Scotland, INTO and UTU in Northern Ireland.
- General unions covering support staff — UNISON, GMB, Unite and Community all have substantial school-support-staff memberships.
What's not a trade union (but offers similar support)
There are also organisations in the school sector that offer individual employment support but aren't registered trade unions. The most prominent is Edapt — an independent membership organisation for school and college staff in England and Wales. Edapt provides professional caseworkers and legal support when individual things go wrong, but doesn't do collective bargaining or call strikes.
These are sometimes described as "trade union alternatives" or "alternative professional support". They're worth knowing about if the collective-action side of trade union work doesn't appeal to you, or if you want apolitical individual cover.
What's a "political fund"?
Some trade unions also operate a separate political fund, which pays for political campaigning. Members can choose to opt out of contributing to this fund. A subset of unions are also formally affiliated to the Labour Party (UNISON, Unite, GMB and Community in the school sector). Affiliated unions pay an extra fee to Labour and have voting rights at the party's conferences.
Teaching-specific unions — NEU, NASUWT, NAHT, EIS — generally have political funds but aren't affiliated to any party. ASCL has no political fund. Edapt has no political fund and isn't a trade union.
Whether any of this matters to you is a personal call. Our quiz asks about it directly so the recommendations match your view.
The TUC and STUC
Most major UK trade unions belong to a federation. In England, Wales and Northern Ireland that's the TUC (Trades Union Congress); in Scotland it's the STUC. The TUC coordinates union work nationally and represents unions in dealings with government. Not every union is a TUC affiliate — ASCL is the main exception in education — but most are.
So... should you join one?
That's a separate question, with a longer answer in our do I need a union? guide. The short version: most UK teachers and school staff do join something, mainly for the individual protection. Whether you join a trade union or an alternative like Edapt depends on what you want from membership.
Last updated: 26 May 2026.