Nintendo Online family account question

So I only have have one switch. My oldest son's. However, myself and my youngest use it on occasion. We use our own accounts. Will I need a family plan to allow my youngest to play Mario Kart online ok his account or would a single on my oldest account suffice? Hope I explained that well enough. Thanks in advance.

I was trying to find out the exact same info for the exact same reason and as far as I can tell, yes, we will need to buy a Family Plan if we want both accounts to be able to get online, play NES games, cloud save, etc.  Sucks.  $35 is way less attractive than $20.

Ah well. I wonder if you can upgrade a a single to a family after the fact. Thanks for the information.

I think the service goes live tomorrow. More information will be available to hopefully answer everything.

I believe yu ahve a week to signup, online will be free for one week from what I have heard.