Xbox live on a Child Account

Same issues. Couldn't migrate the offline account to a LIVE account for a child on the xbox. Had to set the account up online which generated a GamerTag. When I then went to the offline child account on the xbox it asked for the adult login to verify
- did that - then it said the email address for the child account was already associated with an Xbox Live account. The only thing I could do is create a new profile on the Xbox. It's ridiculous there is no way to associate the new Live Account/Gamer Tag
to the exisiting offline account for a child account.

It could be because your xbox live account is a childs account. Child accounts cannot play rated M games.

Hello Travis,

As you may be aware 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.

For this reason you need to have access to the parental account in order to 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.

For further information check this link:

support.xbox.com/.../online-safety

Problem:

You see the following error and message when you try to sign in to Xbox Live using a child account:

Before you can sign in here, you'll need to sign in at Xbox.com.

An adult will also need to sign in so they can give permission.

Code: 83118853

This means that the parent account must provide permission for each associated child account (under age 13) before the child can access Xbox Live

Solution:

To resolve this issue, have the child account sign in to Xbox.com. Then, when prompted, the parent account associated with the child account should sign in to Xbox.com and give permission for the child account to sign in to Xbox Live.

If you keep experiencing the problem, contact Xbox Support.

You can't change a child account into an adult account once registered for xbox live. You can modify the DOB under your MS account's page yet that will not upgrade a child account into an adult account for the live service.