Nintendo Account

The Nintendo Account is basically your My Nintendo account. It is used for Nintendo apps and websites and for the Switch eshop system.

Its predecessor account, the NNID, can be linked to it; if you want to buy NNID content directly from a Nintendo website, you will also need to fuse their eshop balances. Linking a NNID is needed if you want to register digital purchases on WiiU and 3DS for Gold points.

It can be set up (including NNID link) via https://accounts.nintendo.com.