An image forming apparatus comprising: an image forming unit configured to form an image on a printing medium (P); and a control unit configured to calculate distance information between a portable electronic device and the image forming apparatus, wherein the distance information includes information on a first area (R1), a second area (R2), and a third area (R3) divided according to a distance between the portable electronic device and the image forming apparatus, wherein when the portable electronic device enters the first area, the control unit is arranged to request authentication information of a user from the portable electronic device, and when the authentication information of the user is received from the portable electronic device, the control unit is arranged to perform a user authentication operation based on the received authentication information and wherein when the portable electronic device enters the second area, the control unit is arranged to perform the image forming preparation operation, wherein when the portable electronic device enters the third area, the control unit is arranged to perform the image forming operation, the image forming apparatus being characterised by being adapted to check whether the user has received the printing medium formed with the image and in that when the portable electronic device is moved away from the image forming apparatus, the control unit is arranged to perform an unreceived printed material warning operation depending on whether the printing medium formed with the image is received by the user, and/or to perform a printed material receiving assignment operation depending on whether the printing medium formed with the image is received by the user. an image forming unit configured to form an image on a printing medium (P); and a control unit configured to calculate distance information between a portable electronic device and the image forming apparatus, wherein the distance information includes information on a first area (R1), a second area (R2), and a third area (R3) divided according to a distance between the portable electronic device and the image forming apparatus, wherein when the portable electronic device enters the first area, the control unit is arranged to request authentication information of a user from the portable electronic device, and when the authentication information of the user is received from the portable electronic device, the control unit is arranged to perform a user authentication operation based on the received authentication information and wherein when the portable electronic device enters the second area, the control unit is arranged to perform the image forming preparation operation, wherein when the portable electronic device enters the third area, the control unit is arranged to perform the image forming operation, the image forming apparatus being characterised by being adapted to check whether the user has received the printing medium formed with the image and in that when the portable electronic device is moved away from the image forming apparatus, the control unit is arranged to perform an unreceived printed material warning operation depending on whether the printing medium formed with the image is received by the user, and/or to perform a printed material receiving assignment operation depending on whether the printing medium formed with the image is received by the user. <EOS>