The meanwhile in the everyday business established electronical invoice, the so-called "E-Invoice", is more and more used by companies for the secure exchange of invoices.
Many appropriate classifications as e.g. the "qualified electronical signature" or the "advanced electronical signature" are offered by webPDF for the digital signing of PDF documents according to the legal framework.
Thereby webPDF can be reliably used for E-Invoice. More information about webPDF is available here.