The policy brief provides an overview of the findings, lessons learnt, and recommendations for tackling undeclared work from four years of data gathering and research in three SEE countries, namely Bulgaria, Croatia and Macedonia. It underlines the fact that participation in undeclared work is a widespread and accepted practice in the economic and social life of Southeast Europe, yet this phenomenon differs substantially across and within the three countries. As some of the countries from SEE have already joined the EU while others have embarked on a path to accession, designing policies to tackle the problems of undeclared work has become priority for most governments in the region. Therefore, the governments in Bulgaria, Croatia, and Macedonia need to embark on a comprehensive agenda of understanding and tackling the undeclared economy. The current policy brief contributes to the better understanding of the complexity of the issues governments in the region face and provides policy recommendations, which emphasize curative, preventative and commitment measures in addition to the widely preferred repressive measures.