Electricity and water tariffs are undergoing significant changes due to smart metering, retail competition, and regulatory changes. Consumers now have to choose between different tariffs which are getting more and more complex. Theoretically, these new tariffs aim to use more cost-reflective pricing to incentivise consumers to adopt the right behaviours. However, empirical evidence from real pricing shows that consumers are confused by the complexity. Based on a lab experiment, this paper investigates how electricity and water consumers adopt more or less complicated tariffs and adapt their behaviours accordingly. We show that subjects prefer simple tariffs over complex ones. However, when they receive adequate information about tariffs and appropriate behaviours, they choose more complex tariffs. These results argue in favour of self-selection of tariff forms, in order to account for consumers’ different abilities to respond to the price signal. Lastly, we discuss the appropriateness of using a price mechanism to incentivise consumers.