Aim: The article explores secondary school students' perceptions of the 'value' of UK curriculum subjects; alongside what, how and why specific subject value attribution patterns are important for students, and the psychological impact of this on their wellbeing and academic self-efficacy beliefs (SEB). Method/Rationale: A mixed-methods, sequential design was used. Stage 1 explored students' value attribution for specific subjects; and relationships between attribution patterns, SEB and wellbeing. Stage 2 further explored and explained Stage 1 findings. In Stage 1, attainment data and questionnaires were collected from 38 Year 9 students. Thematic analysis explored students' value attribution for subjects, while Mann-Whitney and t-tests explored the relationships between attribution patterns, SEB and wellbeing. In Stage 2, nine participants were interviewed, and relationships identified were thematically analysed. Findings: Three superordinate themes (perceived usefulness, external factors and lessons' characteristics) justified the subject attributed value, highly biased towards English Baccalaureate (EBacc) subjects. Students with strengths in non-EBacc subjects had significantly lower SEB than students with strengths in EBacc subjects; similar results were found for students with strengths in subjects they had not identified as 'important' versus students with strengths in subjects they had identified as 'important'. Wellbeing measures did not yield statistical differences. Stage 2 findings suggested students with strengths in EBacc subjects felt cleverer, as their skills were respected by peers and appreciated by teachers; EBacc subjects were perceived as more 'academic' than non-EBacc subjects. The timetabling and the EBacc's academic value were identified as adverse factors for non-EBacc subjects, alongside fewer opportunities to progress in and receive positive feedback for skills in non-EBacc subjects. Conclusions: As previous literature indicates SEB relate to education and employment opportunities, the research suggests potential future educational and social inequalities for students with strengths in non-EBacc subjects, problematic for social justice.