Children who live in Sweden without a legal residence permit have the right to go to Swedish school. Students are thereby welcomed at the same time as they are considered illegal in society at large. In this qualitative study based on interviews, I rely on an explorative approach towards Swedish Compulsory School policy practice and the way it affects the schooling opportunities of undocumented children. Findings include how policy interpretation and enactment involves secrecy and socially compensatory acts. The school policy practice of secrecy is primarily enabling schooling opportunities for undocumented children. However, it also conditions these opportunities as participation presupposes concealment and self-restraint in order for the undocumented student to remain incognito. This ambivalence is identified on macro, meso, and micro-levels, as the ambiguous state policies are built into the school organization and reproduced on the school floor. Schools’ social compensatory support is partly expressed through challenges and resistance against unjust policy practices, and partly through civil commitment. The result show that schools’ social support relies widely on the arbitrariness of individual school agents; a commitment that stems from a situationally emerging ethical responsibility to aid undocumented students. It is thereby recognized as vulnerable, as the social support for undocumented students depends on individual agents.