Tradeshift , which has been described as the “Skype for invoicing”, has announced a raft of new partners in the SaaS accounting space, along with plans to open up its API to enable more third-parties to tie into its free invoicing system. The launch partners who have had access to a beta version of Tradeshift's API include: ERPLY (free ERP system), E-conomics (a SaaS accounting solution provider), Workbook (a specialized platform for the media business), Office123 (an open-source ERP system), Continia (bank payments systems), Winfinans (Windows-based desktop accounting), and Ibistic (the leading e-invoicing workflow system in Scandinavia). This, says the company, in which early Skype investor Morten Lund is an adviser , puts it on track to bring "directly integrated electronic invoicing" to more than 100,000 small European businesses over the next 6 months.