<p>In tracked educational systems, students are sorted into hierarchical secondary education tracks, based on track recommendations at the end of primary education. While socioeconomic status (SES) has been consistently linked to higher track recommendations, less is known about its role in track transitioning during secondary education. Furthermore, the influence of school-level SES (average SES composition of a school) on these outcomes has been underexplored. Therefore, the aim of this study was to examine SES-related disparities in both track recommendations at the end of primary education and track transitioning during secondary education, while disentangling the effects of both student-level (L1) and school-level (L2) SES. Utilizing longitudinal data from 673 primary schools (<i>n</i> = 17,918 students) and 190 secondary schools (<i>n</i> = 3,271 students), multilevel analyses were conducted to disentangle these effects. Results indicate that SES-related disparities are primarily situated at the student-level (L1); students from higher-SES backgrounds were more likely to receive higher track recommendations and experience upward track transitioning in comparison to their lower-SES peers, even when controlled for achievement. However, the effects of student-level SES on both track recommendations and track transitioning varied significantly between schools, with some schools granting lower-SES students the benefit of the doubt while others adopt a more cautious approach. Particularly in higher-SES schools, lower-SES students were more likely to receive lower track recommendations and to transition downward compared to their higher-SES peers. School-level (L2) SES did not independently influence track recommendations or track transitioning. The findings of this study underscore the importance of considering both student-level factors and between-school variability when addressing SES-related disparities in track recommendations and track transitioning.</p>