Borderlands, as spaces of various forms of entrepreneurial activities, offer rich examples of informal entrepreneurial activities that depend on the border location to be developed and sustained. Although the socioeconomic contributions of informal activities have been widely acknowledged, little research has been conducted on the ways that enlargement of the European Union (EU), by affecting the openness/closedness of borders, affected the nature and extent of cross-border informal entrepreneurial activities (IEAs). Recognizing the heterogeneity of border regions, in terms of formal and social institutional structures, linguistics and ethnicity, the paper offers a nuanced and extended understanding of the difference the geography of borders, broadly defined, makes to the diversity and persistence/disappearance of cross-border IEAs since EU enlargement. Using qualitative data from interviews collected with households involved in cross-border IEAs in several EU border regions, the paper indicates that cross-border IEAs have a time dimension, reflected in the pre- and post-enlargement changes to the intensity of these activities, as well as a regional dimension, reflected in various dichotomies such as impoverished/affluent, socioculturally proximate/distant and hard/soft borders, reflected in the forms, enablers and constraints of such activities. The paper illustrates how the spatial, economic, institutional and sociocultural characteristics of a context overlap, dominate or recede at different points in time to facilitate/inhibit different forms of entrepreneurial behaviour and to encourage the involvement of, or empower, different groups of people. Thus, context, in all its dimensions, remains an important factor for spatial and temporal explanations of cross-border IEAs as particular forms of entrepreneurial activity.