In principle, yes. With your contract number and login code you can log in to your neon account on any device on which the neon app is installed. In order to make payments, however, you'll have to activate the «new» device. To do so, you can create an activation code on the device on which your neon account is already active (i.e. your «old» device) by going to «Profile», clicking on «Security», and «Generate activation code». Then, enter this activation code in the neon app on your «new» device in the «Profile» tab under «Activate device».