<p>Helping colleagues is a behavior that is common in the workplace and highly relevant for organizational effectiveness. The consequences of helping for the <i>helper</i> is an emerging field of research with mixed findings. Taking the potentially differential nature of reactive and proactive help into account, the present study focuses on the social consequences of help for helpers. Drawing on theory that highlights the fundamental human need to belong as central to psychological functioning, we propose that reactive help positively affects individuals’ sense of relatedness and, subsequently, affective organizational commitment, whereas the effect of proactive help depends on a characteristic of the helping exchange. Specifically, we propose that the level of perceived acceptance of the proactive help shapes the extent to which proactive help may contribute to or impair the sense of relatedness. We tested our model with a daily diary study (<i>n</i> = 110; <i>k</i> = 508) with four daily measures (before work, morning, afternoon, end of day). Multilevel path analyses support the proposed positive effect of reactive help on evening organizational commitment, mediated through afternoon experience of relatedness. The effect of proactive help depended on the extent to which helpers perceived that their help was accepted by the recipients of their help. This research underscores the distinct nature of reactive and proactive help, highlighting how helping may either support or hinder individuals to feel connected to their workplace.</p>