The pilot, which starts in a few months, has been spearheaded by the Welsh First Minister Mark Drakeford and builds upon a Senedd pledge made by a cross-party group of 25 MSs following work encouraged by the UBILab Network. This pledge has also been supported by the Welsh Future Generations Commissioner Sophie Howe, charged with ensuring that every public decision taken in Wales considers the future impact on society. A UBI is a regular cash payment given without conditions and is not means-tested. In this article we assess how a UBI can guarantee the prosperity of future generations in Wales, and why this is socially and economically important for the UK and the rest of the world. It is written while we prepare our new book on Universal Basic Income, to be published next year.