Pre-enrolment self-assessments are a promising way to address student commitment and retention in an early stage. Such assessments aim to inform study decisions by evoking reflection and providing advice for further preparation. Though these assessments require a solid validation process, so far the consequential validity aspect tends to be ignored. To address this gap, the current study investigates self-assessment impact on study choice certainty and enrolment as well as self-assessment fairness. Prospective students (N = 662) orienting towards studying in higher online education took a self-assessment consisting of six subtests. The impact appeared in line with the assessment's purpose for 68.9% of the prospective students: their study choice certainty was adapted or remained unchanged in accordance with their obtained scores. Study choice certainty after the self-assessment related positively to enrolment probability. Additionally, the impact appeared fair (similar across subgroups), though men's study choice certainty appeared relatively robust against unfavourable scores.