Founded in 1982, the UK u3a movement (based loosely on the French model) aims to encourage groups of people no longer in full-time work to come together and continue their enjoyment of learning subjects of interest to them.

Each u3a is a member of the Third Age Trust, having signed an agreement when they were formed and renewed each year. Individual u3as are not branches of the Trust but are instead operationally independent organisations. Nationally there are 1400 u3as with over four million members.

All u3as are run by volunteers and are mutually supportive. There is a national office which has paid members of staff helped by volunteers to support the u3as and ensure that u3as all conform to legal requirements.

The Board of Trustees are responsible for overseeing governance of the Third Age Trust, ensuring it is well run for the benefit of its members. The Board ensures full compliance with all relevant laws and regulations, and works with the u3a Council to ensure the u3a voice is central to the strategy development process. Trustees are elected by u3as nationally and are themselves u3a members.

Council Representatives report to the Council on behalf of the u3as, and the Chair of the Council reports regularly to the board to highlight any concerns u3as may have. Council Representatives are elected by the u3as in their Region and are themselves u3a members and volunteers.

To facilitate learning, each u3a has a range of groups covering a large number of subjects. Groups are led by members for members. No qualifications or prior knowledge is needed, simply an interest in the topic the group covers.