This guide reviews Council of Europe provisions on social security co-ordination, covering the European Convention on Social and Medical Assistance, the European Convention on Social Security, the Model Provisions for a Bilateral Social Security Agreement, and the European Social Charter. It describes the basic philosophies behind social security co-ordination, why it is needed and how it may be achieved; as well as considering practical aspects of the range of legal instruments available and briefly introducing some of the agreements that are currently in force in Europe.