If you are producing invoices for one or many businesses, Office Stuff recommend you take a look at SliQ Invoicing & Quoting produced by UK software company SliQTools.
SliQ Invoicing is a professional invoice programme especially designed to be easy to use but still produce professional results. Using a swish, modern user interface, closely modelled on Office 2007, raising an invoice takes a matter of seconds. SliQ comes with a range of configurable invoice templates and allows you to add your own logo to your invoices. Customer payments can be easily tracked and SliQ will even highlight overdue invoices.
SliQ Invoicing Templates & Screenshots