The invention relates to an image forming system having plural image forming apparatuses. In the image forming system, a first communication unit in an first image forming apparatus is controlled to transmit first data to a fifth communication unit in a portable terminal. The fifth communication unit is controlled to transmit second data to a third communication unit in a second image forming apparatus. Each of the first and second data includes image data specifying information and communication setting information. A fourth communication unit in the second image forming apparatus is controlled to establish second type communication between the second communication unit and a fourth communication unit in the second image forming apparatus based on the communication setting information. The fourth communication unit is controlled to transmit, to the second communication unit, request for transmission of image data specified by the image data specifying information. The second communication unit is controlled to transmit the image data to the fourth communication unit.