Steps for updating the country/region setting for a Nintendo Account.
Important: The country/region settings for child accounts (12 and under) cannot be changed individually. If the family group admin changes their own country/region setting, the child accounts in the family group will have their country/region settings updated automatically.
What to do
Go to the Nintendo Account website and sign in to your Nintendo Account.
Select User Info.
In the “Profile” section, select Change.
In the “Country/region” dropdown, select the desired country/region.
Select Save changes.
Read the information about changing your country/region, then select I agree to confirm the change.
If you receive a message that you have a Nintendo eShop balance that must be spent, please read the below information on this issue for assistance.
Your Nintendo eShop balance does not carry over when you change your Nintendo Account country/region setting. You will need to use the remaining funds before you can change your country/region or they may be permanently lost.