I can't seem to find any way to update my now legacy details since moving country.
My general apple account has changed just fine but my developer account still shows as UK and no way to update.
Any ideas?
Update membership details
Your question seems related to Developer Account I would recommend you to contact the developer account support at https://developer.apple.com/contact to make sure they can help you with the changes if you can't do it online.
Albert WWDR