Recent changes in patterns of public service provision, sometimes associated with the ‘regulatory state’, have been said to have eroded citizenship and diminished accountability. This paper responds to these challenges by outlining a toolbox of four transparency mechanisms – information, choice, representation, and voice – as alternative devices that can be built into the architecture of public service regimes, to increase responsiveness and answerability. Using insights drawn from cybernetics and transaction cost analysis, this paper looks at the consequences of different choices of combinations of mechanisms in allocating authority in line with competing administrative doctrines of fiduciary trusteeship and consumer sovereignty. Attention is drawn to differences in ‘cost profiles’ between different public services that can facilitate or inhibit consumer choice as a basis for understanding the suitability of different combinations of mechanisms to specific public services. A contingency model determining the suitability of particular mechanisms to particular services of different ‘cost-profiles’ is presented. Given the variety of public services and among different public service architectures in the regulatory state, it is argued that this differentiated approach to transparency and accountability provides a more effective response to holding public services accountable than narrower traditional notions of political accountability.