There are a couple of ways to update your country code and save it into your existing addresses
Go to your address book and update your desired address
During the checkout process, select the country code and then select the checkbox to save your address in the checkout process. Save using the same name to update your existing address in the address book.
The exception is that we cannot update your myTI address currently to include this on your cart. Our suggestion is to change your default to another address by going to your address book and selecting “Set as default” to another address.