Brussels is a capital city located in Western Europe, bordering France, Luxembourg, The Netherlands, and Germany. The Brussel Capital Region had about 1.23 million residents in 2022. Brussels is a superdiverse city that is home to an astonishing 184 nationalities. In 2021, about 83% of Brussels residents had a migration background.

According to most recent estimates , the number of undocumented immigrants in Belgium is around 112.000. In 2020, 11,495 persons were found to be present without authorization in Belgium and 20,230 non-EU citizens were ordered to leave the territory. About 52.000 people, or the majority of undocumented migrants in Belgium, reside in the Brussel Capital Region. Of the homeless population living in the Samusocial centers in Brussels, it is estimated that around 70% does not have a valid residence permit.

Despite the regularizations of 1999 and 2009, Belgian migration policies have become increasingly restrictive offering few pathways to citizenship to undocumented migrants and investing primarily in forced and voluntary return. In response to the local presence of undocumented migrants, local initiatives have been taken by welfare institutions, homeless shelters and municipalities to secure undocumented migrants to basic social services. However, migrants on the move continue to be barred from state-run shelters even when they are still in an asylum procedure. This situation has resulted in the visible presence of migrants on the move surviving in the streets of Brussels. Informal solidarity initiatives and self-organizations have emerged in recent years to address this situation.

In light of the above, we consider Brussels to be an important arrival city for undocumented migrants in Western Europe. The URBIMM project seeks to better grasp how the field of urban migration infrastructures is structured, how they engage in local service provision and policy practices towards undocumented migrants and how this affects the mobility trajectories of migrants on the move in and beyond Brussels.