The European project initiative TRUST will produce knowledge and guidance to support TRansitions to Urban Water Services of Tomorrow, enabling communities to achieve sustainable, low-carbon water futures without compromising service quality. We deliver this ambition through close collaboration with problem owners in ten participating pilot city regions under changing and challenging conditions in Europe and Africa. Our work provides research driven innovations in governance, modelling concepts, technologies, decision support tools, and novel approaches to integrated water, energy, and infrastructure asset management. An extended understanding of the performance of contemporary urban water services will allow detailed exploration of transition pathways. Urban water cycle analysis will include use of an innovative systems metabolism model, derivation of key performance indicators, risk assessment, as well as broad stakeholder involvement and an analysis of public perceptions and governance modes. A number of emerging technologies in water supply, waste and storm water treatment and disposal, in water demand management and in the exploitation of alternative water sources will be analysed in terms of their cost-effectiveness, performance, safety and sustainability. Cross-cutting issues include innovations in urban asset management and water-energy nexus strengthening. The most promising interventions will be demonstrated and legitimised in the urban water systems of the ten participating pilot city regions. TRUST outcomes will be incorporated into planning guidelines and decision support tools, will be subject to life-cycle assessment, and be shaped by regulatory considerations as well as potential environmental, economic and social impacts. Outputs from the project will catalyse transformatory change in both the form and management of urban water services and give utilities increased confidence to specify innovative solutions to a range of pressing challenges.