An electronic invoice is a computer-generated tax document which replaces the corresponding physical printed document whilst retaining the same legal validity.
Physically, an electronic invoice is an electronic file containing all the invoice data plus a sequence of characters called an electronic signature. It is this electronic signature which affords the electronic invoice full legal and tax validity and does away with the need to receive the physical document.
No, it will only be valid for viewing. For the invoice to be valid for tax purposes, the conditions that appear each time the service is accessed must be accepted. Once accepted, these conditions will not appear again and the printed invoice will no longer be received.
From the moment invoices are requested*, independent of when the Electronic Invoicing section was first accessed.
* From January 2006.