Your HP printer gets offline when it is not able to make connection with your computer system. At this time, first of all you need to ensure that both printer and computer are securely connected with a USB cable. If you are using a wireless printer, then make sure printer is turned on and it is connected with the similar Wi-Fi network in which your computer is. If all are well connected and printer is still showing offline error, then you need to take the HP Printer Customer Care Phone Number. The experts available there will guide you towards the effective methods to help you out in eliminating HP printer error in an easy manner.