To perform processing by optimum scheduling by utilizing a network in order to turn paper actual slip data to electronic data.

In this invention, a data processing center and a plurality of users and a plurality of data entry parts connected through the network to the data processing center are provided. Each user reads an actual slip by a scanner and transmits a read image to the data processing center. The data processing center divides the image received from each user and transmits respective divided images to the different data entry parts. In the respective data entry parts, the received image is turned to the electronic data and returned to the data processing center. In the data processing center, the electronic data returned from the respective data entry parts are merged and integrated code data are returned to the user.