Intellectual Property (IP) is a key intangible asset influencing corporate performance and its management is increasingly recognized as a central element of corporate strategy. Analysts however, have largely focused on IP management within the firm, overlooking the different and pervasive problem of how to manage IP in the context of inter-firm collaborative projects. Here, groups of firms, often competitors, and sometimes their customer organizations, collaborate in the design, development, manufacture and maintenance of complex products. Such collaborations involve exchanges of large amounts of proprietary technical data, facilitated through the use of advanced IT tools. How can organizations exploit the capabilities offered by these tools without increasing the vulnerability of IP assets to misappropriation or leakage? In the UK defense market an extensive set of formal contractual tools are being developed to support IP management in collaborative projects. Through an in-depth study of IP management practice in UK defense projects we analyze the extent to which contractual tools can combine with technical solutions to provide answers to the problems posed by IP management in complex, long-term collaborative projects. We conclude that contractual and technical tools must be underpinned by managerial changes that bring together functions that remain separated in most large corporations: IT management, and legal and commercial departments.