Patent ID: 7389063

Claim:
An image formation system including at least two image formation apparatuses interconnected on a network, wherein: a first one of the image formation apparatuses comprises an input device operated to input user identification information, a first user register registering user identification information of a user authorized to use said first image formation apparatus, a first verifier performing a verification as to whether the user identification information input via said input device matches that registered with said first user register, a tandem apparatus register registering a different image formation apparatus performing tandem print, a generator generating a plurality of tandem print data from print data, and a transmitter operative in response to said first verifier providing a successful verification to transmit to a second image formation apparatus registered with said tandem apparatus register said tandem print data together with verification information indicating that the verification has succeeded; and said second image formation apparatus comprises an input device operated to input user identification information, a receiver receiving print data, a second user register registering user identification information of a user authorized to use said second image formation apparatus, a second verifier performing a verification as to whether the user identification information input via said input device matches that registered with said second user register, and a controller providing control to perform an image formation process without said second verifier's verification if print data received from said receiver includes information of verification by a different image formation apparatus.