When bad things happen people often seek out close others for support to help regulate their negative emotions. The degree to which support providers are responsive to the specific needs of support seekers is associated with many outcomes, including how effective that support is in regulating emotion. The ability of support providers to accurately assess the emotions experienced by support seekers seems crucial, yet few studies have examined the role this type of accuracy plays in support provision. We predicted that individuals who accurately assessed the emotions being experienced by a support seeker would provide more responsive support. Further, we predicted that individual differences in emotion differentiation (perceiving differences between similar emotions), range (experiencing a range of emotions), and clarity (understanding the cause and effect of one's emotions) would facilitate emotional accuracy and, in turn, responsiveness. Participants read scenarios depicting their romantic partners seeking support to help regulate different negative emotions; they then wrote supportive messages and indicated which emotions they thought their partners would be experiencing. Individual differences in emotional range and clarity (but not differentiation) predicted how accurate participants were in gaging the emotions depicted in the scenarios. In turn, accuracy predicted how responsive their messages were, as rated by independent coders. These results suggest that accuracy in perceiving a partner's emotions is crucial for providing responsive support and individual differences in one's own emotional experiences are associated both accuracy and responsiveness. Our findings have implications for research on interpersonal emotion regulation, close relationships, and social support. (PsycInfo Database Record (c) 2020 APA, all rights reserved).