Once you login to your account online, you'll be able to change some of your details. The information you can see and update will depend on the type of account you have-
If you have a Studio Pay credit account - you will be able to update your billing address, phone number, credit limit & statement preferences. To do this, head here. ( https://pay.studio.co.uk/my-account )
For other order-related details, or if you pay in full during checkout - you'll be able to see and update your delivery addresses. Please note, you will not be able to make changes to an order (such as change the address, or add/remove items) after it has been placed.