Purpose: This paper aims to outline considerations for trust management between established national identity federations in education and research. It also aims to discuss policy issues related to cross-federation and to compare existing academic identity federations. The paper seeks to investigate Nordic national federations and to introduce the Kalmar Union as a means of interconnecting the Nordic federations. Design/methodology/approach: The paper discusses various issues in the policy of a cross-federation, and suggests further work for developing the Kalmar Union Charter. Findings: The paper finds that the technology used in federated identity management becomes more and more standardised, the technological challenges in making cross-federations become fewer. Therefore, the remaining obstacles seem to be missing legislative know-how, causing lack of sound information for decision makers. Thus, in an identity federation, trust establishment is, in the first place, a policy issue, not a technical one. Originality/value: In recent years, several identity federations have been established in higher education around the world. Existing federations have a national scope, but the need for cross-border services has led to the first interconnects of national federations. The Kalmar Union has been established as a cross-federation of the Nordic academic identity federations. (Contains 5 notes.)