This survey data report examines the main findings on the supply side of undeclared work around the EU based on a Special Eurobarometer survey carried out in 2013. The report examines the survey methodology, the concept of undeclared work, the characteristics of those supplying goods and services on an undeclared basis, the types of work activities that are undeclared, and income levels from undeclared work, including the extent of the practice of offering cash in hand.