Fostering border relations among the people in border regions seems a precondition for
the future envisagement and success of cross-border regions and European Integration. Related
studies to border relations observe the weakness of these informal border contacts and relations.
However, weak ties represent an opportunity for interaction, and little has been said about how
they might play in the construction and performance of institutional cross-border cooperation
(CBC). In this work, we examine the nature of personal border networks of professionals working
in CBC and how they are interconnected with the institutional CBC. This paper is based on a
mainly qualitative research of two different border regions: Andalusia, Algarve and Alentejo
(AAA) and South Finland and Estonia (SFE). Nevertheless, the methodology is multi-method,
using semi-structured interviews, with specific questions for applying a social network analysis.
Conclusions point out different patterns of border relations in both border regions. In AAA, most
of the cross-border relations are weaker and related to their professional involvement in
institutional CBC. In SFE, border relations rely both on working and personal reasons. All of
these cross-border relations imply a significant value as opportunities for social capital
construction across the borders and, hence, for greater interaction and cross-border integration.