The essence of an electronic invoice is that instead of printing it out on paper, it is only issued and transferred digitally. The seller and the buyer stores it in its electronic form, and the National Tax and Customs Administration of Hungary (NTCA / NAV) will review them through its online service. An electronic invoice (e-invoice) contains the same information and looks the same as a paper-based invoice. An e-invoice is equivalent to a paper-based invoice, and because of its digital signature and digital timestamp, it fully complies with the legal requirements about archiving invoices. The invoice created with our invoicing system is just a single PDF file that has been digitally signed and timestamped.