Cities and city regions are back on the research agenda in the UK. Taking the world city literature as a guide, this article uses advanced producer service firms to study contemporary inter‐city relations in the UK space economy. We employ an interlocking network model, initially developed for global scale analysis, to assess signs that recent globalization is effecting a revival outside the London region, and to identify leading urban areas in the UK national economy. Two different analyses are presented: a connectivity analysis, which indicates how well cities and towns are linked into the UK space economy, and a fuzzy clustering analysis, which classifies the cities and towns in order to search out hierarchical and regional tendencies. From these findings, we identify two distinctive polycentric city‐regional processes in contemporary Britain: a Jacobs‐style polycentric mega‐city regional process out of London, which creates new important service centres and reaches selected smaller cities and towns; and a polycentric multi‐city regional process beyond London, which mainly enhances the service capacities of selected larger cities. A concluding section considers the implications of the two processes for spatial planning in the UK.