Abstract: Systems, methods, and computer program products for processing transactions involving an exchange of an electronic document, such as a ticket redeemable for a travel service. Data defining related transactions is stored in a transaction database. In response to detecting the occurrence of a transaction involving a tracked document, a transaction history of the document is retrieved from the transaction database. A plurality of payment events is extracted from the transaction history and filtered by document type and form of payment to determine a set of payment events with forms of payment that are refund-eligible. The refund-eligible forms of payment are aggregated, and the aggregated forms of payment ranked. A residual amount associated with the exchange is reconciled across the ranked aggregated forms of payment by one or more payment events. The payment events are then added to the transaction history of the tracked document in the database.