Access to water and sanitation are recognized as human rights by the United Nations, reflecting their vital importance to every person's life. At a fundamental level - delivering minimum standards of water services to meet basic human needs - it is a simple equation. People are rights-holders and States are responsible under international law to provide those services. Rights-holders can claim their rights and duty-bearers must guarantee the rights to water and sanitation equally and without discrimination. This paper explores the relationship between the human rights to water and sanitation, the Sustainable Development Goals, water services and the role of water service tariffs in helping or hindering delivery of a broad range of societal objectives, including human rights and sustainability. Two key questions emerge: (i) What are the rights that apply in these circumstances and who is responsible for addressing those rights? (ii) How can the viability of the water service system be maintained without imposing dramatic price increase, and without compromising the social and human right to water in good quality and affordable conditions? In this paper we argue that human rights to water and sanitation, and the tariffs that are applied to them, should not be addressed as technical problems but rather as social and political issues of justice. We conclude that the re-politicisation of water, and of the setting of water tariffs, would help ensure that the responsibilities upon Governments for delivering human rights to water and sanitation are clear.