A mailing machine is provided that, when operating in a differential weighing mode, can detect if a user has replaced one or more mail pieces that may have been inadvertently removed at the same time back onto the scale. If the mailing machine detects such replacement within a predetermined time period after the scale has stabilized, the weight calculated for the mail piece can be reduced by the amount added back to the scale, or, alternatively, the user could be requested to confirm that multiple pieces were inadvertently removed from the scale at the same time, the user is trying to correct that error, and a new weight is to be determined.