Invoices Tied to something other than email?

Just ran this plugin past my client, all set up and configured. She likes it, but would like an option to create an invoice that isn’t tied to an email address. They provide pickup and drop-off laundry services, and frequently schedule service over the phone. Currently, their system is tied to last name and phone number.

Also – is it possible to remove the “subtotal” on the invoice? They do not itemize their bills.

Many thanks,
~KJ

http://wordpress.org/plugins/wp-invoice/