Clients can access their billing control panel within their Site Manager account (yourdomainname.com/manager/) or manage.westhost.com. Please find this by going to the section titled Manage Your Account, Billing, Billing Summary. It is also available under the section Welcome to Site Manager, located under the Site Management, Manage your billing.
You must allow the pop up to view the billing control panel.
Once logged in you can manage the following:
Billing & Services
Manage Payment Card