trying to add my kids icloud and i get message that its invalid address, why

Hi magaly20,

It sounds like you're unable to add your child's Apple ID as an iCloud account on an iOS device, but running into an error that the Apple ID is invalid.

We have a few questions you can review to ensure the setup is correct and linking the Apple ID with iCloud can be completed.

Family Sharing and Apple ID for your child

1. Is the email a valid email address?
2. Is the email verified?
3. Manage the Apple ID and ensure all of the data is accurate at Manage and use your Apple ID including the date of birth.
4. Is the Apple ID setup elsewhere on the device?
5. Check that a valid payment method is setup - Change, add, or remove Apple ID payment methods
6. Does this occur when using a different device to sign in to iCloud, such as the web?

Thanks for posting in the Apple Support Communities forum.

Have a great week!

Hi magaly20,

It's great that you were able to figure out the culprit. Since this is a public forum, you can update the account birthdate by following the instructions here:

Update the birth date associated with your Apple ID

If you're getting an error, Contact Apple Support for additional help.

Take care!