To provide a data output system which outputs target data with a simple operation, and also provide a data output method.

When image data are transmitted from a data registration client 20 to an image server 10, a data management means 12 stores the image data in a data storage means 15, issues an ID specifying the image data, generates charging information, and transmits the ID and the charging information to the data registration client 20. When a user pays a fee based on the charging information, the data registration client 20 issues to a user a card 100 to which the ID is recorded. When the user makes a data output client 30 read the ID recorded to the card 100, the ID is transmitted to the image server 10. The data management means 12 selects the image data correlated to the ID. A data transmission means 17 transmits the image data to the data output client 30.