A printing system including a printer and an information processing apparatus, the printer being configured to receive image data from the information processing apparatus, store the image data, generate image identification information identifying the image data, and transmit the image identification information to the information processing apparatus, the information processing apparatus being configured to store the received image identification information in association with an information-processor user ID, and transmit an inquiry about a login user to the printer, the printer returning a printer user ID of the login user to the information processing apparatus, the information processing apparatus transmitting to the printer a print command and the image data stored in association with the information-processor user ID when the received printer user ID is coincident with the stored information-processor user ID, the printer performing a printing operation based on the received image data.