Thanks for the post , votes, and comments. We are aware of this limitation and are targeting sometime next year to improve this experience. In the meantime you can sign up for a new account in your desired country and transfer your assets to the new account via Support.
-Azure Billing Team
An error occurred while saving the commentTony Baynes commented
Moved from the UK to Spain, and tried to update my Azure profile/billing details, without any success. I am unable to change the country from United Kingdom to Spain. Seriously Microsoft, can't you make it easier to change my details? This seems ridiculous.