This article contributes to the literatures on the governance of activation and the territorial structure of the welfare state by drawing attention to the institutional designs of active welfare states and the architectures of decentralisation, as well as to their manifestations and implications. With the end of capturing dissimilar intergovernmental models of activation, this paper develops a framework of ‘centre–regional’ relations, which we apply to the cases of Italy and Spain – two countries that have devolved active labour market policy powers to their regions but have organised power-sharing structures very differently. The findings suggest that when it comes to active welfare states, horizontal arrangements are linked to salient institutional variations across the territory. By contrast, hierarchical structures, which are characterised by a dominant role of central level governments, are linked to higher levels of cohesion. These findings are relevant as they expose the manifestations and implications of distinct decentralisation models on activation regimes, welfare states, as well as on welfare clients.