How to sign up Like the look of Online Banking? If you want to sign up you can start here. To register for Online Banking: you'll need to be an existing Westpac customer call us on 0800 400 600 (7am to 11pm, 7 days a week) and we'll sort it out over the phone or +64 9 912 8000 from overseas (international toll charges apply) visit us at any Westpac branch If you are already registered for Phone Banking you can use your Phone Banking ID and password. Login now. Already signed up for online banking? Great – simply login.