Skip to content
IT Sign in Start free

Send an invoice to the SDI

How to transmit an e-invoice to the SDI exchange system from your certified email (PEC) or through an intermediary, and what happens next.

Where to find it
Documents → invoice record → Send to SDI

Open in Nanus

What it is for

An Italian e-invoice only exists for tax purposes once the SDI (Sistema di Interscambio, the Revenue Agency’s e-invoicing exchange system) receives and accepts it. After Issue invoice the invoice is a draft saved in Nanus; with Send to SDI Nanus generates the XML file, transmits it and from then on tracks its outcomes.

Before you start: the channel

You choose the sending channel once in Settings → SDI sending and receiving:

  • Company PEC mailbox: invoices leave from your PEC (Italian certified email) mailbox and outcomes arrive in the same mailbox. You need the PEC address and the provider’s SMTP server for sending, plus the IMAP server to read the receipts. It works with any PEC, with no intermediary contract.
  • Aruba: if you have an Aruba Electronic Invoicing API account, Nanus hands the file to Aruba, which signs it, sends it to the SDI and archives it.

If you used another program with the same PEC before, enter the number of the last file sent in Last file number sent: Nanus continues from there, so the SDI does not reject a file name already used.

How to do it

  1. Open Documents, Invoices filter, and tap the number of the invoice to send. On the Home page, under To do, you also see how many invoices are still to be sent.
  2. Check the preview and totals; if you like, open PDF for the courtesy copy.
  3. Tap Send to SDI and confirm. Nanus checks the invoice again, creates the file with a new name and sends it.
  4. The record shows the Exchange System (SDI) section with the Sent to SDI status, the file name, and when and where it was sent.

Once the SDI has delivered it, the invoice can no longer be changed or deleted: to correct it you need a credit note.

After sending

Receipts and notifications update the invoice automatically. With the PEC channel Nanus checks the mailbox while you use the app, at most every 15 minutes, or immediately with Check now; with Aruba outcomes update in the same way or with Update outcomes and received invoices. The possible statuses are explained on the SDI status page.

Common problems

  • “To send to the SDI, enter the PEC address and SMTP server in Settings → PEC mailbox”: the PEC channel is not set up yet.
  • “Sending to the SDI failed”: the PEC server refused the message; the error detail follows in the text (password, port, security).
  • If the invoice has errors, sending stops and the record lists what to fix.
  • “The invoice has already been sent to the SDI”: it has already arrived without rejection; to change it, issue a credit note.

Alternatively you can download the file with More → Download XML and upload it yourself to the Revenue Agency’s Fatture e Corrispettivi portal or to an intermediary. In that case Nanus receives no outcomes and the invoice stays a draft.

Frequently asked questions

Can I send to the SDI from the desktop app?

Yes: the PEC channel works both in the cloud and in the desktop app.

Does the customer receive the invoice on my PEC?

No: they receive it on their own recipient code or PEC, as set in their record. Your PEC is only used to talk to the SDI.

See also