Yes, an internet connection is required to use your Nero account, to activate or register Nero software,to validate your license, and access online services or updates. Offline activation or manual registration on a computer without internet access is not supported. 

For Nero Platinum yearly subscription license, you need Internet and keep your Nero Account logged in all the time, in order to take use of Nero Platinum.

For Nero Platinum lifetime / unlimited / permanent license and Nero Standalone program, Internet is needed when Nero program is running for the first time in order to active your Nero license. After activation, Internet connection is still required at least every 30 days in order to run Nero program. 

There is only one exception. For business solution, e.g. companies, government and educational institutions and all other organizations, we provide volume license program which does not require Internet at all. Please get detailed information and contact volume license sales here: https://www.nero.com/enu/products/business-solutions/index.php