After the post-communist transition, decentralisation and subsidiarity have become one of Poland's major principles of political organisation. Moreover, especially the original 1990 reform and establishment of self-governing communes are regarded as a success story, not only in improving the quality of governance and public service provision but also in the civil society and citizen participation, as evidenced by the development of modern urban movements. The article explores legal possibilities for further decentralisation of municipalities, analysing the role of ancillary units in regional capitals. Ancillary units in Poland have developed differently in the countryside and urban communes. Relying on publicly available information and data provided by the respective municipal offices, the article describes the ancillary units' statutory role, competencies, and actual activities. The findings enable the assessment of the application of the sublocal decentralisation solution in Polish cities and the identification of its benefits and shortcomings.