peer reviewed ; In Wallonia, Belgium's southern region, the distribution component of the overall electricity retail tariff is essentially volumetric, i.e. based on the users' energy consumption (in €/kWh). Residential prosumers, moreover, are connected to the grid via a net-metering system. In this paper, we rely on a sophisticated multi-agent tariff simulator – developed in Manuel de Villena et al. (2019, 2020) – calibrated to this specific regional context to model the integration of prosumers into the distribution grid. This simulator enables us to highlight how the emergence of prosumers impacts the distribution network tariff, and to evaluate several tariff reforms currently under discussion: the introduction of a prosumer fee, the introduction of a capacity component and a switch to net-purchasing. Without a change in the metering system, short run reforms can only change the structure of the tariff paid, either to all consumers or to prosumers only. In the long run, especially thanks to smart meters, we consider both the introduction of a net-purchasing system and of a tariff with a capacity component. Our analysis highlights one key added value of smart meters: they allow network tariffs that are fairer and sustainable.