If your phone number changes, you need to notify Swan at support@swan.io. Since the phone number is used for authentication and approving payments, you'll be asked for a photo of your ID to verify the change.
You can change your email address from the UKKO Business Account interface. Log in to your Business Account and go to the 'Members' section in the menu. By clicking on your details, you can change your email address. Once you save the information, you'll receive a text message with a link to confirm the changes you made.
Remember to also update your contact information within the UKKO Entrepreneur service!