It’s important to have your correct birthday on file with your Apple Account. It’s used in features like Family Sharing and helps provide age-appropriate experiences.
You can edit your birthday in your Apple Account settings or on the web. You can edit a child’s birthday by signing in to their account on the web.
Go to Settings > [your name].
Tap Personal Information. You might need to sign in to your Apple Account.
Tap your birthday to edit it.

Update your birthday, then tap Done. If you’re changing a birthday from an adult to a child, learn more about converting to a child account.
Go to System Settings > [your name].
Click Personal Information. You might need to sign in to your Apple Account.
Click your birthday to edit it.

Update your birthday, then click Done. If you’re trying to change a birthday from an adult to a child, use an iPhone, iPad, or the web instead.
Sign in to account.apple.com with the account you want to edit.
Select Personal Information, then choose Birthday.

Update the birthday and click Save. If you’re changing a birthday from an adult to a child, learn more about converting to a child account.
Depending on how you created your Apple Account, you might be required to provide additional information or change your Apple Account primary user name from a mobile phone number to an email address.
To change a birthday to any age below 131, the account must be a member of a Family Sharing group, and the Family Sharing organizer must approve the change.
If you convert an Apple Account to a child account
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