Recently, there has been increased interest in information sharing among government agencies with a view toward improving security, reducing costs, and offering better quality service to users of government services. Previous work has focused largely on the sharing of structured information among heterogeneous data sources, whereas government agencies need to share data with varying degrees of structure ranging from free text documents to relational data. In this work, we complement earlier work by proposing a comprehensive methodology called IAIS (Inter Agency Information Sharing). It uses XML to facilitate the definition of information that needs to be shared, the storage of such information, the access to this information, and finally, the maintenance of shared information. We describe potential conflicts that can occur at the information definition stage across agencies. We also compare IAIS with two alternate methodologies to share information among agencies and analyze the pros and cons of each.