Nintendo Network ID is a unique identifier made up of 6 to 16 characters that allows you to access certain Nintendo Network services.
By registering a Nintendo Network ID to your Wii U or Nintendo 3DS, you can enjoy a wide range of network services. You can post about your game experiences on Miiverse, our unique network communication service, get access to great downloadable content from Nintendo eShop, and much more.
If you have connected your Wii U to the internet, we strongly recommend you register the same Nintendo Network ID on Nintendo 3DS. Using the same Nintendo Network ID on both systems will combine their Nintendo eShop balances.
In order to create a Nintendo Network ID, you'll need a Wii U console or Nintendo 3DS system and an email address.