A printing apparatus for a printing system comprising a first information processing apparatus (101, 102) and a second information processing apparatus (102, 101), the printing apparatus being provided with a plurality of sheet containers (117, 118, 119, 120, 121) and capable of registering sheet information in correspondence with the sheet containers and capable of updating print adjustment information linked with the sheet information in accordance with a request received at the printing apparatus from the first information processing apparatus (101, 102) executing a sheet management application or from the second information processing apparatus (102, 101) executing another sheet management application, wherein the printing apparatus comprises: retaining means arranged to retain information about one or more information processing apparatus executing a sheet management application by storing an IP address of the information processing apparatus as a connection source in response to a connection request for the information processing apparatus received at the printing apparatus; and a controller arranged to determine, based on the retained information, whether there is already a connection from the second information processing apparatus (102, 101) when a connection request is received from the first information processing apparatus (101, 102) that has started executing the sheet management application, in a case where it is determined by the controller that there is already a connection from the second information processing apparatus, the controller, is further arranged to: when the connection to the first information processing apparatus is determined to be a prioritized connection, transmit information to the first information processing apparatus for displaying an execution screen of the sheet management application and information to the second information processing apparatus for displaying a warning and delete a stored IP address of the second information processing apparatus; when the connection to the second information processing apparatus is determined to be the prioritized connection, transmit information to the first information processing apparatus for displaying a warning and delete a stored IP address of the first information processing apparatus. retaining means arranged to retain information about one or more information processing apparatus executing a sheet management application by storing an IP address of the information processing apparatus as a connection source in response to a connection request for the information processing apparatus received at the printing apparatus; and a controller arranged to determine, based on the retained information, whether there is already a connection from the second information processing apparatus (102, 101) when a connection request is received from the first information processing apparatus (101, 102) that has started executing the sheet management application, in a case where it is determined by the controller that there is already a connection from the second information processing apparatus, the controller, is further arranged to: when the connection to the first information processing apparatus is determined to be a prioritized connection, transmit information to the first information processing apparatus for displaying an execution screen of the sheet management application and information to the second information processing apparatus for displaying a warning and delete a stored IP address of the second information processing apparatus; when the connection to the second information processing apparatus is determined to be the prioritized connection, transmit information to the first information processing apparatus for displaying a warning and delete a stored IP address of the first information processing apparatus. when the connection to the first information processing apparatus is determined to be a prioritized connection, transmit information to the first information processing apparatus for displaying an execution screen of the sheet management application and information to the second information processing apparatus for displaying a warning and delete a stored IP address of the second information processing apparatus; when the connection to the second information processing apparatus is determined to be the prioritized connection, transmit information to the first information processing apparatus for displaying a warning and delete a stored IP address of the first information processing apparatus.