As low socioeconomic status (SES) and ethnic minority students often experience barriers during their school career, increased levels of referral of these students to extramural support services in education (ESS) can be expected. Yet, research indicates that disadvantaged students are often underrepresented in different types of ESS. The purpose of this study is to examine possible social inequalities in the use of, and referral to, ESS (study 1) and to explore the experiences of disadvantaged students' parents (study 2). In study 1, 3302 parents of school-aged children completed a survey on the use of ESS. Data were analysed using logistic regression analyses. In study 2, parents of disadvantaged school-aged children (N = 8) participated in focus group discussions, which were analysed thematically. Results of study 1 confirmed the unequal use of ESS according to family SES and migration history, and revealed that inequality was especially prominent in private ESS, whilst subsidised ESS was equally used. Schools did not refer low SES and ethnic minority students more to ESS. In study 2, disadvantaged students' parents addressed the role of multiple thresholds beyond merely financial barriers in decision processes pertaining to ESS use. Results indicate varying degrees of social inequality in the use of subsidised and private ESS. Such dynamics of unequal access and participation can reinforce unequal education opportunities. Addressing disadvantaged families' subjectively experienced thresholds may provide one way to reduce this inequality. When disadvantaged families do not reach the necessary ESS, schools should compensate and increase their guidance for these students.