Italy — Sistema di Interscambio (SDI)

TL;DR

• E-invoicing has been mandatory in Italy since 2019 for B2B and B2G; B2C since 2022.
• Every invoice must transit Agenzia delle Entrate's SDI hub; you can't bypass it.
• Native format is FatturaPA XML. Flowie auto-converts UBL ↔ FatturaPA and routes via SDI for you.
• Each invoice must be addressed via a Codice Destinatario (7 chars) or, for unregistered recipients, via certified email (PEC).
• SDI delivers three receipts per invoice: RC (delivered), NS (rejected), or MC (recipient unreachable). Flowie surfaces these as webhook events.

Background — the SDI flow

Italy was the first country in the world to mandate B2B e-invoicing through a centralized hub. The flow:

Sender ERP → Intermediary (Flowie) → SDI → Recipient
                                       ↓
                                 Receipts (RC/NS/MC) ← back through Flowie

Flowie acts as your registered intermediario. We submit invoices on your behalf, store them for the legally-mandated 10 years, and forward SDI receipts to your webhook.

Codice Destinatario

Every Italian recipient has a Codice Destinatario (CD) — a 7-character routing code that tells SDI where to deliver. Three flavors:

To resolve a CD from a SIRET-equivalent (Italian Codice Fiscale), use:

curl …/v1/companies/resolve?countryCode=IT&vatNumber=IT01234567890 \
  -H "Authorization: Bearer $KEY"
# → response.additionalIdentifiers includes "codiceDestinatario"

FatturaPA & UBL — when to care

SDI accepts only FatturaPA XML 1.2.2. If you send Flowie UBL or JSON, we transcode to FatturaPA before submission to SDI. The reverse is true for incoming: we transcode FatturaPA → UBL so your stack only ever deals with one format.

If you must send raw FatturaPA (e.g. you already generate it from your ERP):

curl -X POST …/v1/documents/send \
  -H "Authorization: Bearer $KEY" \
  -d '{
    "type":"invoice",
    "format":"ubl-xml",
    "from":"comp_…",
    "to":"0211:01234567890",
    "xml":"<?xml version=\"1.0\"?><p:FatturaElettronica …>…</p:FatturaElettronica>"
  }'

Required fields for Italian invoices

• seller.additionalIdentifiers[codiceFiscale]required

  11- or 16-character Italian tax code. Auto-populated on company creation from the registry.

• buyer.additionalIdentifiers[codiceDestinatario]required

  7-char CD or 0000000 + buyer.contact.pec.

• document.note (TipoDocumento)required

  SDI document type: TD01 standard invoice, TD04 credit note, TD16 reverse-charge, TD17 intra-EU services, TD24 deferred invoice, …

• document.lines[].vatCategoryrequired

  Italy uses Natura codes (N1–N7) on top of standard rates. Required when vatRate = 0.

• payment.discountTermsoptional but enforced

  If present, endDate must precede document.dueDate. SDI rejects otherwise (00400).

Document types — TipoDocumento (TD)

Every Italian e-invoice carries a TipoDocumento (TD) code that tells SDI what kind of document it is — ordinary sale, credit note, self-invoice, integration for reverse charge, and so on. Set it via document.note (we map it into the FatturaPA <TipoDocumento> field). Picking the wrong TD is a common cause of business-side errors and of scarto codes 00471–00474.

Deep dive & interactive explorer: the full referential — every code filterable by family, click-to-detail with the rules and the exact Flowie call, plus a deep dive on each family — is on the dedicated Document types explorer. The table below is the summary.

The complete current set (Agenzia delle Entrate guide v1.10, April 2025). Numbering jumps from TD09 to TD16 by design — TD10–TD15 do not exist.

Self-invoice TDs need seller = buyer. For TD16–TD27 (integrations / self-invoices) SDI checks the cedente/prestatore against the cessionario/committente: TD20/TD21/TD27 must have seller = buyer (00472), the foreign-purchase TDs require a non-IT seller country (00473), and ordinary TD01 must have seller ≠ buyer (00471).

Lifecycle & SDI receipts

SDI returns a sequence of asynchronous XML messages. The full set (official fatturapa.gov.it definitions), and how each maps to a Flowie event:

Flow: send → checks fail ⇒ NS (stop, fix & resend) · checks pass ⇒ delivery: success ⇒ RC (+ MT to recipient) · temporary failure ⇒ MC · permanent failure ⇒ AT. B2G only, after delivery the PA may return EC01/EC02 (relayed to the sender as NE); no answer in 15 days ⇒ DT. Private B2B/B2C have no accept/reject step — the recipient cannot formally refuse via SDI, so RC / MC is the terminal state.

SDI scarto codes — reasons for a Notifica di scarto (NS)

When SDI rejects (scarta) a FatturaPA file it returns a NS carrying one or more of these codes. The file is not fiscally issued — correct and resend within 5 days keeping the same number and date. Authoritative list: fatturapa.gov.it Elenco controlli v1.7. The codes below are the complete set, grouped by what they check.

Nomenclature, transmission & uniqueness (00001–00102, 00404)

Schema & signature integrity (00400-class structural)

Sender / recipient identity & routing (00300–00330)

Amounts, VAT & rounding (00400–00430)

TipoDocumento ↔ parties consistency (00471–00474)

Where the code lands in the API. A scarto surfaces on the document.failed webhook and on GET /v1/documents/{id} as error.code (the 00xxx value) plus a human-readable error.message and, for schema errors (00200), an error.details[] array naming the offending XML element/xpath.

Testing your Italian integration

FAQ

Do I need a separate authorization in Italy?

No. Flowie's intermediario credentials cover all our customers. You just need to grant us the SDI delegation in your Fisconline account once — the dashboard walks you through it.

What about the 10-year storage requirement?

Italian law requires every B2B invoice to be archived for 10 years in a "conservazione sostitutiva" environment. Flowie's archive complies with the Agenzia delle Entrate technical specs (DPCM 03/12/2013). No extra cost.

Can I send a paper invoice in parallel?

Legally, no — only the SDI-transmitted version counts. You can send a courtesy PDF copy via email, but it has no fiscal value.

References

Primary sources (Italian government & EU regulator):

• Agenzia delle Entrate · Fatturazione elettronica — Official taxpayer portal; technical specs, FAQ, ramp dates.
• FatturaPA · official portal — FatturaPA reference site (formats, schema, examples).
• Specifiche tecniche fatturazione B2B v1.9 — Authoritative XML schema and validation rules (PDF).
• IndicePA — Public-administration directory for B2G Codice Univoco lookup.
• Fisconline / Servizi IVA — Where you delegate Flowie as intermediario for SDI submission.
• Decreto Legge n. 66/2014 (Normattiva) — Foundational law mandating B2G e-invoicing.
• Legge di Bilancio 2018 · Art. 1 cc. 909-928 — Extension to universal B2B clearance from 2019.
• EU Commission · eInvoicing in Italy — Pan-EU reference factsheet.
• OpenPeppol · Italy profile — Peppol BIS interaction with SDI.

Industry analyses (cross-reference for the SDI mechanics):

• Sovos · Italy SDI mandate guide — Industry tracker — clearance model details.
• Pagero · Italy compliance updates — Industry compliance tracker.