Can't Promote Child Account to Adult Account

You may need to promote your account from a child account to an adult account. please follow the following link to promote your account to an adult account and then try again: support.xbox.com/.../promote-child-account

Xbox Live determines whether an account is a child account or an adult account based on the age of the account owner. Child accounts are tied to an adult's Microsoft account.

After you reach the age of adulthood (which varies by country and region), you can promote a child account to an adult account. This promotion can be done only from the parent's account

I believe if your account is 18 or older but is a child account can you promote it yourself on the dashboard by going to the Xbox Dashboard > Settings > Account and if you get a prompt that says "Promote to Adult" you can do it from there. That's how i did
it.

If its 17 or younger, the adult account has to promote you.

If its 17 or younger and you have no clue on what the adult account is, then you gotta make a new account.

More info at
support.xbox.com/.../promote-child-account

But I think support can't make changes to your age. Sorry.

If you want to promote a 'Child' account to an adult, please refer to this website:

support.xbox.com/.../promote-child-account

If you can't remember the parent account used to verify, now that you're over 18, you can simply promote the account:

Promote a child account to an adult account in Xbox

Xbox LIVE determines whether an account is a child account or an adult account based on the age of the account owner. Account owners who are younger than 18 are given child accounts in the United States. The legal adult age varies by country and region (for
example, the adult age in Korea is 20).

Child accounts are tied to an adult's Microsoft account. The adult account can control Family Settings and restrict some features of Xbox LIVE.

After you reach the age of adulthood (which varies by country and region), you can promote a child account to an adult account. This promotion removes the Family Settings and Xbox LIVE restrictions.

To promote a child account to an adult account

• Sign in to Xbox LIVE by using the account that you want to change.
• Go to Settings, and then select Account.
• Select Promote Child Account.
  Note The age of an account owner is calculated by using the date of birth provided when the account was created. This date cannot be changed. If you entered an incorrect date of birth when you created the account, your only option is to create a new
  account using the correct date of birth. This option is available only if the date of birth for the account indicates that you have reached the age of adulthood (18 in the United States). The legal adult age varies by country and region.
  
• Follow the on-screen instructions to promote the account.