This research paper published by Terre des hommes, looks at the intra EU migration of Romanian and Bulgarian children to France and Greece in situations of vulnerability. It focuses on the return procedures that are used by countries and assesses the latter in the light of the principle of the best interests of the Child as enshrined in the Convention on the Rights of the Child to which all EU Member States have adhered. Although the research faced a series of limitations which hindered its accuracy, the present research conclusions and recommendations remain based on a 16-month data collection process which allowed to gather information on 97 individual cases of children for whom the authorities have or should have found durable solutions. The main recommendation of the research proposes the creation of a standardised procedure applicable in the 27 Member States that would foster internal and transnational coordination in order to properly assess the situation of children and find durable solutions that have been jointly designed with the children concerned, thereby leaving an important space for their participation.