PurposeThe aim of this paper is to evaluate the degree to which there is cross‐national cooperation when tackling undeclared work and how the fight against undeclared work in Europe might be more effectively coordinated.Design/methodology/approachA multi‐stage inductive approach is used involving a web survey of 104 senior government officials, trade unions and employer organisations in 31 European countries, 33 follow‐up in‐depth explanatory interviews, four two‐day focus groups in European regions involving 44 stakeholders, and a European‐wide focus group of 20 stakeholders.FindingsCollaboration between European countries is currently partial and very limited when tackling undeclared work. To more effectively collaborate, the consensus amongst the participating stakeholders is that an inclusive network of experts covering the tax, social security and labour aspects of undeclared work needs to be developed which engages in information sharing, capacity building and operational cooperation not only on the issue of cross‐border undeclared work but also combating undeclared work at the national level.Research limitations/implicationsUntil now, the literature on undeclared work has not evaluated the extent and nature of cross‐national collaborations to tackle this phenomenon. This paper fills that gap.Practical implicationsThe paper reports the consensus reached amongst pan‐European stakeholders on how to more effectively broker knowledge on a multilateral cross‐national basis to tackle undeclared work.Originality/valueThis is the first evaluation of cross‐national collaboration in relation to tackling undeclared work in Europe.