Levels of co-operation between government bodies, semi-state agencies, community groups and private industry in Northern Ireland and the Republic of Ireland are increasing rapidly with respect to issues such as coordinated infrastructure planning, health care, trade and enterprise, as well as peace and reconciliation. These initiatives require joined-up thinking and detailed rationales for their formation and funding, which in turn are dependent on evidence-based arguments. However, at present, providing consistent, coherent and reliable evidence on a cross-border basis for use at different scales is extremely difficult due to issues of data interoperability across the jurisdictions. In other words, data are often incompatible and therefore difficult to compare. Addressing issues of data interoperability is crucial to successful cross-border, evidence-based initiatives.