Peppol vs SDI in Italy

Italy is the European e-invoicing oddity. Most EU countries with mandatory or upcoming mandates have either chosen Peppol as the channel (Belgium, Norway, the Nordics) or are building Peppol-aligned national systems (France, Germany). Italy did neither. It built SDI in 2014, made it mandatory for B2G that same year, and then rolled it out to all B2B transactions on 1 January 2019. SDI is the only legal channel for a domestic Italian invoice today. It is run by the tax authority and every invoice flows through it in real time.

That does not mean Peppol is absent in Italy. AgID, the Italian Digital Agency, is the Italian Peppol Authority and there are certified Italian Peppol Service Providers. Peppol coexists with SDI for cross-border flows, certain procurement use cases, and as a bridge for foreign sellers who already have Peppol but no SDI integration.

Practically, the question for any business that has to invoice an Italian customer is not which network do I use, it is how do I get my invoice into SDI. For Italian businesses, the answer is the SDI intermediary you use through your accounting software. For foreign sellers, the answer is often a Peppol-to-SDI bridge.

SDI is a five-corner system. The seller hands the invoice to its intermediary (corner 1 to corner 2), the intermediary submits it to SDI (corner 3), SDI validates and routes it to the buyer's intermediary (corner 4), which delivers it to the buyer (corner 5). SDI is the centre of the network and every document passes through it.

The format is FatturaPA, an Italian XML schema. FatturaPA is broadly aligned with EN 16931 but adds Italian-specific extensions: detailed VAT codes, support for ritenuta (withholding tax), the codice destinatario buyer routing code, and mandatory qualified electronic signature on B2G invoices. The seller signs the invoice (qualified e-signature) when required, packages it as a FatturaPA XML, and submits it to SDI through their intermediary.

SDI validates the document: schema check, signature verification, formal field checks, codice destinatario lookup. If valid, it routes the invoice to the buyer's intermediary and stores a copy. The Agenzia delle Entrate uses that copy for real-time VAT reporting; this is what makes SDI a five-corner / digital reporting system rather than just a delivery network. The buyer's intermediary delivers the FatturaPA file to the buyer's accounting system.

Every step is mandatory and SDI is the only valid route. There is no “PDF as fallback” the way there still is in many other countries. An Italian-to-Italian B2B invoice that does not go through SDI is not legally valid and will be rejected for VAT purposes.

Even though SDI is mandatory inside Italy, Peppol is not absent. There are three main scenarios where Peppol matters in Italy:

1. Cross-border invoices to Italian buyers. Foreign sellers, especially in countries with mature Peppol adoption (Belgium, the Netherlands, the Nordics), can send their invoices over Peppol BIS Billing 3.0. Italian Peppol Service Providers operate a bridge that converts the Peppol UBL invoice into FatturaPA and submits it to SDI on the recipient's behalf. From the foreign seller's point of view it is a normal Peppol delivery; from the Italian buyer's point of view it arrives through SDI like any other invoice.
2. Cross-border invoices from Italian sellers. An Italian business that wants to invoice a Belgian, Dutch or Norwegian buyer in Peppol format can do so via a Peppol-capable intermediary, while still meeting the SDI obligation for the domestic-side reporting via the EsteroMeteo / TD-17 / TD-18 / TD-19 mechanisms.
3. Public procurement and special use cases. AgID has specified Peppol for some procurement scenarios where an EN 16931-compliant invoice in UBL form is preferred over FatturaPA, particularly for cross-border procurement covered by EU Directive 2014/55/EU.

In all three cases the Peppol leg is real and certified, and the SDI leg is real and mandatory. They coexist rather than compete.

If you are a non-Italian business with Italian customers, you have three practical options:

• Use a Peppol-to-SDI bridge provider. Send the invoice via your existing Peppol Access Point. The bridge provider converts to FatturaPA and submits to SDI for you. This is the path of least resistance if you already have Peppol capability.
• Onboard directly with SDI through an Italian intermediary. Contract with an Italian SDI provider, generate FatturaPA documents, submit them through their channel. This is more direct but requires implementing FatturaPA in your accounting system or relying entirely on the intermediary's tooling.
• If your sales to Italy are very low volume, talk to your Italian customer about their preferred route. Many large Italian buyers will accept Peppol via a bridge they have already set up; smaller customers may prefer that you use their own SDI provider.