Change email address of an account

The Online Store Customer Care is only able to change the email address of your store account, however not of your membership account. To do this, please contact our Square Enix Central Support team through the following link:

https://support.eu.square-enix.com/contact.php?id=612&la=2

Then choose "Account/Billing" as Contact Category and "Update Email Address" as Contact Sub-category.