This presentation introduces an updated determination of the Gauss–Listing geopotential value W0, a fundamental quantity for the realisation of global vertical reference systems and modern height datums. The study revisits earlier methodology using contemporary global datasets, including recent mean sea surface models, ocean dynamic topography information, and a high-resolution global gravity field model, all treated consistently within the same tide system. An independent normal-gravity formulation is also used to define a new best-fitting global reference ellipsoid satisfying U0 = W0 The presentation discusses how the updated W0 realisation and associated ellipsoid contribute to a physically consistent reference surface for geoid computation, gravity-field modelling, and the unification of vertical height systems.