Standard plans can have one extra member, and Premium plans can have two.

 Standard plans can have one extra member, and Premium plans can have two. 

So far, Netflix hasn't offered an option for these "extra member" fees on its Basic plans, which now are available in some countries as two options: a pricier Basic account that's ad-free and a cheaper Basic With Ads. In the US, the ad-free Basic tier is $10 per month, and the ad-supported level is $7 a month. (For context, a US Standard plan is $15.50 and Premium is $20.)

Both the ad-free and ad-supported Basic plans limit your viewing to a single simultaneous stream, which makes account-sharing functionally difficult.Do extra member subaccounts have any limitations? Yes. Extra member subaccounts get only one simultaneous stream, and downloads can be stored on only one phone or tablet at a time. 

They also can have only one profile, which can be entirely new or it can be based on a profile transferred from another account. While this single extra-member profile can set different maturity ratings, it can't be a Kids profile, which has a special look and feel designed specifically for children. And an extra member must create the subaccount in the same country as the main account owner. (But once activated, the extra member can watch from anywhere.)