All you have to do is save your invoice in QuickBooks as you would normally do. FCC Accounting System for QuickBooks Italy will then pick up that invoice and send it to your customer, transmitting it to the Italian SDI and saving the result as an attachment to your original QuickBooks Invoice.

All you have to do is to set your VAT number in QuickBooks as instructed by FCC and note what your assigned SDI code is. You will also have to enter your new SDI code "Codice Destinatario" on the italian government website "Agenzia delle Entrate". After doing that, the next supplier sending you an electronic invoice will immediately trigger a new vendor bill in QuickBooks, containing all the required information and the original attached invoice. Refer to FCC for support in english and to QUICKBOOKS ITALIA for support in italian.

You have to use FCC ACCOUNTING SYSTEM. The mandatory "Liquidazione Periodica IVA" is an XML file that will be automatically generated with the data from QuickBooks. After downloading the file, you can upload it to the "Agenzia delle Entrate" website.

Italian trasmission of self invoices to "Agenzia delle Entrate" is mandatory. The procedure to do a self invoice in QuickBooks is the following: 

Record a supplier bill in QuickBooks and select one of the VAT codes provided by FCC that implies self invoicing

Open FCC Accounting System and, after reviewing the resulting self invoice, click on the button that transmit that invoice to the government

It is important to know that, just like customer electronic invoices, once a self invoice is transmitted to the government, it can't be deleted from QuickBooks