From NCH Software:
Express Invoice is professional invoicing software for Windows that allows you to manage client accounts, create invoices, and apply payments. You can then print, e-mail, or fax your invoices to your clients directly from the application. This software allows you to create re-occurring invoices for ongoing services and link to credit card gateways to easily process payments for goods and services. Express Invoice also includes a number of standard reports such as unpaid accounts, payments, sales person, accounting reports. Express Invoice allows you to send invoices by e-mail or fax. Automatically send statements to customers with overdue payments. Configure the layout of invoices including the invoice title, alignment, font size, and foot comment.