Trade unions
U
| Full Name | Short Name | Notes |
|---|---|---|
| Undeb Cenedlaethol Athrawon Cymru | UCAC | |
| Union of Construction, Allied Trades and Technicians | UCATT | |
| Union of Patternmakers | UPM | |
| Union of Post Office Workers | UPW | |
| Union of Print Workers | UPW | |
| Union of Shop, Distributive and Allied Workers | USDAW | |
| Union of Textile Workers | UTW | |
| UNISON | UNISON | |
| Unite | Unite | Formed on 1 May 2007 by the merger of Amicus and the Transport and General Workers' Union. |
| United French Polishers' Society | UFP | |
| United Patternmakers' Association | UPA | |
| United Textile Factory Workers' Association | UTFWA | |
| Unknown | Unknown | |
| UPW | UPW |