Given the scope and importance of migration in the 21st century, a comprehensive and cooperative approach to "the management of international migration" is required to provide benefits for both individuals and societies alike; to be successful this cannot be undertaken unilaterally or by governments alone. In this article, the need for applied linguists and language testers to contribute to this approach is discussed, and a case is made for the relevant linguistic and assessment considerations to be addressed within an agreed frame of reference. The case is made for a clearer understanding of "the migrant's journey" and more precise identification of the various participants who need to be brought together so that the issues involving language assessment in the context of migration and citizenship can be addressed more effectively. The current trends are illustrated by describing the changing nature of migration in the United Kingdom over the past 20 years. Ways forward are suggested by looking at some recent examples of successful collaboration of the kind envisaged. (Contains 4 footnotes and 1 figure.)