Save the Children UK has recognized that children on the move are often exposed to elevated risk of harm and that because they are difficult to characterize and reach while in transit, are underserved. The Oak Foundation has therefore provided a planning grant to Save the Children UK to conduct a scoping study to explore strategies for improving programmatic response for children on the move.  This scoping study includes a literature review of methodologies previously used to collect information on children on the move, and the development and piloting of an assessment tool from which to develop programmes for children in transit.  Columbia University was commissioned by Save the Children UK to undertake the latter part of the scoping study relating to the piloting of a Mobile Assessment Tool (MAT) for children on the move that would gather information about children’s evolving needs and coping mechanisms throughout the course of their journeys.  Columbia University was tasked with leading an initial pilot study to test the effectiveness of the MAT and to offer recommendations for future tests.  Initial development and piloting of the MAT took place in Limpopo province, South Africa—the border region with Zimbabwe—and in Thailand on the Lao PDR border. However, the MAT is intended to be adaptable to disparate contexts in which children migrate.