Main issue that I can see with this is compliance. As some people commented these free invoicing templates are great, but if you happen to invoice someone in Mexico or anywhere else in the world this template won't really help.

The reason why we are seeing so many startups in this space is because all major companies, such as Ariba that provide e-invoicing tools are charging suppliers for sending e-invoices, which is ridiculous.

Tradeshift (Disclaimer I do work for Tradeshift ), was one of the first startups that emerged in this space because they provide free and fully compliant e-invoicing software for small businesses. Take a look at how they launched, slightly outdated but funny http://www.realsupplierchoice.com/