A data transmission system is provided that enables a user to move away before the completion of data transmission regardless of whether a refund is made in association with occurrence of a communication error when a data transmitting apparatus performs data transmission and collects a consideration. The data transmitting apparatus includes a consideration receiving portion that receives a consideration of FAX data transmission, a report destination input portion that inputs a report destination of a user, and a FAX transmission error detecting portion that detects a communication error at the time of the FAX data transmission. In case the FAX transmission error detecting portion detects a communication error, the system including the data transmitting apparatus transmits refund information for refunding the consideration of the FAX data transmission with the communication error to the report destination input through the report destination input portion.