In this chapter I describe how private-sector services are being mobilised to deliver water and waste-water services by water-sector organisations in the developed economies to countries with economies that are in a developing phase. Their needs are different because the policy contexts (politics and governance), standards and risks experienced by entities installing and improving water services in the two are different. It will be shown that the international water-sector companies have evolved a diverse suite of financial and contractual arrangements, often in association with international financial institutions (e.g. the World Bank). I will also examine how the water sector is evolving, as new companies shape their financial and technical competence to operate and compete internationally.