Italy Updates SDI Technical Specifications to Version 1.9.1, Adds TD29 Document Type
Agenzia delle Entrate published version 1.9.1 of Italy's e-invoicing technical specifications on 31 March 2026, mandatory from 15 May 2026. The update introduces the TD29 document type for reporting omitted or irregular invoicing, plus stricter VAT-group and sports-worker compensation controls.
Italy's tax authority, the Agenzia delle Entrate, has updated the technical specifications that govern every invoice passing through the Sistema di Interscambio (SDI) — the clearance system underpinning FatturaPA. Version 1.9.1 was published on 31 March 2026 and became mandatory for all transmissions from 15 May 2026: invoices sent to SDI in the previous schema version from that date are rejected.
What's New in Version 1.9.1
The update introduces four specific changes:
A New Document Type: TD29
Previously, businesses had no official SDI channel to report a case of omitted or irregular invoicing by a counterparty to the Agenzia delle Entrate — the kind of situation a buyer discovers when a supplier fails to issue a required invoice, or issues one that doesn't comply with the rules. Version 1.9.1 adds document type code TD29 specifically for this: an XML file transmitted through SDI that formally notifies the tax authority of the irregularity.
VAT Group Controls
Tightened validation rules affecting how invoices are handled when either party is part of an Italian VAT group (Gruppo IVA), reducing a category of errors that previously passed SDI's checks but caused downstream reconciliation problems.
Sports Worker Compensation (IRPEF Exemption)
New handling for invoices covering compensation paid to amateur sports workers under Italy's IRPEF exemption regime, reflecting recent changes to how these payments are taxed.
Recipient Codes and Channel Accreditation
An update to the maximum number of recipient codes permitted for accredited transmission channels, along with revised accreditation procedures for businesses and intermediaries connecting directly via web service (WS) or SFTP — the direct-integration channels typically used by software vendors and larger structured companies rather than the free web/app portal.
Why This Matters
SDI validates every invoice against the current schema before it reaches the recipient — an invoice built to the old 1.9 schema submitted after 15 May 2026 is rejected outright, not merely flagged. Any business or software vendor transmitting FatturaPA invoices directly (rather than through a fully managed third-party service that handles schema updates automatically) needed to confirm their generation and validation logic was updated before the cutover.
What Italian Businesses Should Do
- Confirm your invoicing software or provider is validating against schema 1.9.1 — most major Italian accounting platforms (Fatture in Cloud, Aruba, TeamSystem) pushed this update automatically ahead of the 15 May deadline, but businesses using custom WS/SFTP integrations should verify directly.
- If you've encountered a supplier who failed to issue a required invoice, ask your accountant about the new TD29 reporting channel rather than relying on informal complaint routes.
- VAT groups should re-test invoice flows given the tightened validation rules, particularly for intra-group transactions.
Source
Agenzia delle Entrate, Specifiche tecniche versione 1.9.1 — utilizzabili dal 15 maggio 2026.
