This paper comments on three aspects of POLYNET's implementation of the GaWC model to measure functional polycentricity at the local scale. These aspects are: (i) the use of APS office locations as a proxy for inter-city relations, (ii) the problematic calculation of the functional polycentricity index, and (iii) the rather narrow conceptualization of functional polycentricity. Alternative methodologies are introduced and implemented based on transaction link data to examine whether Central Belgium displays features of a functionally polycentric mega-city region. The results suggest that this is not the case. When it comes to service procurement by large companies in Belgium, Central Belgium displays more features of a hierarchical urban system with Brussels as dominant service city than of a functionally polycentric urban system. We do, however, find some indications for preliminary urban network formation.