Follow the below steps to Update your Billing Address.
Navigate to Addresses
Existing Address
- Click Edit next to the address you want to make your primary Billing Address.
- Tick the box "Use as my default billing address" and then Save Address. You can also make the address your general default here (default shipping and billing address)
New Address
- Click "Add New Address"
- Enter all of the address fields in, including phone number, and tick the box "Use as my default billing address" and then Save Address. You can also make the address your general default here (default shipping and billing address)