HOW TO MAKE USE OF E-INVOICE APPLICATION?
1-
 Taxpayers, who issue limited number of invoice, are able to make use of it via E-Invoice Portal which becomes available in “www.efatura.gov.tr” and created in order to make people use main functions related to E-Invoice via internet.
2- Taxpayers, who issue in a large number of invoices and are in need of various invoicing and have developed information systems, are able to make use of E-Invoice system by means of integrating information systems with E-Invoice system.
3- Taxpayers, who issue in a large number of invoices or are in need of various invoicing, are able to receive and send E-Invoice via information system of a special integrator having technical competence in the event that their information substructure is not enough or they wouldn’t like to operate information systems.

Source: Revenue Administration