A data resolution system provides users with the ability to access and create associations between data items tagged in documents as part of an initial process of identifying data items to be tagged in the documents. Thus, the user that is adding tags to the documents is able to identify related data items from other data sources and create links with those data sources. This ability to identify links at the time of tagging reduces the need for later searching of data sources for related data items. Additionally, the system automatically stores information regarding each link so that information regarding the linked data items may be viewed alongside the original document and/or further information regarding the linked data item is easily accessible. Data items that are tagged in a document may be associated with data items representing the same object, but with different identifiers, names, etc. in external data sources.