3 kids have own accounts?

Each separate account needs to have their own Gold subscription. The best deal is the yearly rate at 60.00. This applies for the 360.

The Xbox One does it a bit differently as everyone can share the content loaded on that console.

Wow this is crazy. I have my account and my 3 kids accounts. $100 was a sweet deal. No way will I go to $240. Not only do we use the 4 accounts, but we all have our own xbox.

you say they are playing under your microsoft account, they in fact all need their own accounts.

create 3 new accounts for the kids and as they are kids it will ask for an adult account, then it creates a family with your account being the parental one.

this will give you parental controls over theirs and they can all play then.

It's worth mentioning as well, that you don't have to have all accounts be gold, although with the family plan you get 4 gold accounts for $99 and that is less than the price of 2 gold accounts normally. At my house, we have 1 gold account (mine) and 3 silver
accounts so that my kids each have their own saves and whatnot.

It is recommended to create a separate (free) account for each of your kids.

Also do NOT use your own adult parent account for your kids.

You should create a separate account for each of your kids with the proper birthdate entered in the account (so the Xbox service can enable online and privacy settings specifically for children), and if not already done so, create an adult account for yourself.

Then you can
add your children to your parent account, and
control what the kids are allowed to do (or not allowed to do) on the console.

With each kid having their own account, they can later go separate ways when they get older, and take their own gaming progress with them.

With one shared account for both your kids, it's like giving one kid the crossword puzzle that the other kid has already solved and filled out.

Thanks to the Xbox One's "Home Console" feature, each kid can play the other kid's games on their own account. So it's sufficient, if one kid buys a game or a Xbox Live Gold membership for online multiplayer.

The other kid can then benefit from the Gold membership, as long as the owner account of the Gold membership enabled the console where both kids play on as their "Home Console" (on the console under Settings->Personalization).

If you have further questions about "best practices" for child accounts, please feel free to ask here. We're here to help!