Can you possibly be more specific about invoicing as self-employed by sending a web link or something?
www.redpepper.org.uk It is still common for electronic remittance or invoicing to be printed in order to maintain paper records.
en.wikipedia.org Their e-commerce platform offers a comprehensive range of e-commerce tools including: ocean schedules, booking, shipping instructions, bill of lading, tracking and tracing, electronic invoicing, and reports.
en.wikipedia.org The tasks that now consumed a pharmacist's day -- customer management, inventory control, and invoicing -- weren't taught in pharmacy school.
www.slate.com It can be used to generate food costs, stock control, order sheets, recipe cards, sales revenue, electronic ordering and invoicing.
www.hospitalitymagazine.com.au