Abstract: A system for annotating transactions includes a computing server configured to retrieve annotation requirements for transaction accounts of an organization client, where the annotation requirements specify a data field of a third-party platform's schema that is used to organize transaction data. The organization client may further specify which transactions need to be annotated using selection criteria. The computing server processes transactions incurred using the transaction accounts and identifies unannotated transactions using the selection criteria. End users who are responsible for annotating the unannotated transactions are provided direct links to annotate the unannotated transactions. Upon receiving annotations from the responsible end users, the computing server can display annotated transaction data for an administrator of the organization client.