The challenges resulting from increasing digitalization and globalization require flexible continuing education for white-collar workers. Especially informal learning becomes increasingly important in the modern workplace. Practitioners want to promote informal learning among employees, researchers want to unveil conducive contextual conditions for informal learning, but they lack an appropriate, validated measure. Based on the octagon model of informal workplace learning (Decius et al., Human Resource Development Quarterly, 2019, 30, 495-535) and an existing 24-item scale for blue-collar workers, we present a short version of eight items for use among white-collar workers.Using three independent samples of 695, 500, and 3134German employees, we show that the second-order factor structure-following the multidimensional octagon modelhas a better fit compared with a model in which all items load on a single factor. The short scale is strongly correlated with the original full scale. The scale's reliability is satisfying (α = 0.76/0.77/0.85; ω = 0.78/0.78/0.86), considering the heterogeneous conceptual nature of informal learning.Regarding criterion validity, we found theoretically expected correlations with job demands, job autonomy, knowledge/skill acquisition, age, and self-directed learning