Italy E-Invoicing SDI 2026: TD29 and v1.9.1 Explained

How Agenzia delle Entrate's May 2026 technical update reshapes compliance obligations for foreign companies holding an Italian VAT number

#155 · LANG: English (en) · AREA: Ongoing Support for Foreign Companies Operating in Italy · TYPE: FAQ / People Also Ask · MODEL: Sonnet 5 · SEO 84/100 · Flesch Reading Ease 36 · fonte: batch_articles_15items_2026-08-14_h20-08_tim9.doc

URL: https://panatolawfirm.com/en/italy-e-invoicing-foreign-companies-sdi-2026

ABSTRACT: The Agenzia delle Entrate, Italy's tax authority, updated the technical specifications of the Sistema di Interscambio (SDI) to version 1.9.1 on 15 May 2026, introducing more than 100 tighter format controls and a new document type, TD29, that directly affects how foreign companies with an Italian VAT number (partita IVA) manage missing or irregular invoices. Combined with an automated VAT assessment mechanism operative from January 2026, the reform raises the compliance stakes considerably for any non-Italian business operating through the Italian VAT system.

Does my foreign company need to use SDI for Italian invoices?

The answer depends on one fact: whether your company holds an Italian VAT number (partita IVA).

Under Law 205/2017 (Legge di Bilancio 2018), every entity registered for VAT in Italy must issue and receive domestic business-to-business invoices exclusively through SDI, the Italian government's invoice interchange hub, in FatturaPA XML format. This applies regardless of where the entity is incorporated. A German GmbH, a UK limited company or a US corporation that has registered a partita IVA — whether through a permanent establishment, a fiscal representative or a direct identification — is fully subject to the SDI obligation / this requirement.

The position of a foreign company without a partita IVA is different. If your entity supplies goods or services to an Italian business without being VAT-registered in Italy, the Italian buyer handles the tax exposure through the reverse-charge mechanism or self-invoicing. You are outside the SDI mandate entirely. The dividing line is VAT registration, not corporate nationality.

Unlike in most common-law jurisdictions, where invoicing formats are a matter of commercial practice rather than statutory requirement / legal mandate, Italy treats the FatturaPA XML format as a hard legal requirement. There is no grace period for legacy templates once registration exists. An invoice issued in PDF or any format other than FatturaPA XML by a VAT-registered entity is legally non-existent for Italian tax purposes — it cannot be used to deduct input VAT and exposes the issuer to penalties. English-speaking businesses accustomed to emailing PDF invoices to Italian clients should treat this contrast as a fundamental shift in approach, not a procedural nicety.

What is the FatturaPA XML format and how do I comply?

FatturaPA XML is a structured data format mandated by the Agenzia delle Entrate. Every field — taxpayer codes, line-item descriptions, amounts, tax rates — must comply with the official schema. SDI validates each file before transmission; a file that fails validation is rejected and never reaches the counterparty.

Version 1.9.1, operative from 15 May 2026, tightens over 100 format controls. In practice, this means that ERP and accounting systems configured to the prior schema may now generate files that SDI rejects outright. Foreign companies that built their Italian invoicing process around internal templates rather than a certified Italian software provider face the highest exposure here.

For cross-border transactions, document type codes are critical. TD17 covers integrations for services received from abroad; TD18 covers EU goods acquired under intra-Community purchase rules; TD19 covers goods already physically in Italy purchased from a non-established foreign supplier. Selecting the wrong document type is not a harmless clerical error: it misclassifies the VAT treatment and attracts scrutiny from / flags the return for introduced in January 2026 (see below).

Practical compliance requires three steps. First, confirm that your ERP or invoicing software has been updated to the v1.9.1 schema — this is a vendor issue, but it is your legal liability. Second, ensure that every invoice submitted through SDI carries the correct document type code for the underlying transaction. Third, appoint or verify your fiscal intermediary (the intermediario fiscale) who submits files to SDI on your behalf; their authority / appointment must be up to date and their software certified.

What is the TD29 document type in Italy's SDI system?

TD29 is the most operationally significant addition in version 1.9.1. It is a self-reporting document type designed for situations where your Italian counterparty has failed to issue an invoice, or has issued one that is irregular, and the 90-day window to correct the position is running.

The rule derives from the obligation under Article 6, paragraph 8 of Legislative Decree 471/1997, as amended / as in force under: the buyer who has not received a compliant invoice must self-report the transaction and pay the related VAT, or face a penalty equal to the full amount of tax evaded (not merely a fixed fine). TD29 provides the formal SDI mechanism for doing this. The 90-day clock runs from the date on which the invoice should have been issued.

For a foreign company purchasing goods or services from Italian suppliers, TD29 introduces a monitoring obligation that many businesses have not previously built into their accounts-payable processes. If an expected Italian supplier invoice does not arrive within the normal commercial cycle, you cannot simply chase the supplier informally. Once the legal deadline approaches, you are required to file TD29 or face the penalty regime. Operationally, this means AP teams need to track Italian supplier invoice receipt against the 90-day limit, not merely against payment terms.

The Agenzia delle Entrate published the updated technical specification document — Specifiche Tecniche versione 1.9.1 — through the official SDI documentation portal. Foreign companies and their Italian tax representatives should confirm that their systems map TD29 correctly before processing any invoice anomaly after 15 May 2026.

Do I need to keep Italian e-invoices for 10 years?

Yes — but the SDI archive and the legal retention archive are two entirely separate systems, and confusing them is one of the most common errors foreign companies make.

SDI acts as a transmission channel, not an archive. Once an invoice is validated and delivered, SDI does not guarantee long-term access. Your legal obligation to retain Italian tax documents for 10 years flows from Article 8 of Legislative Decree 39/2021, which implements the Codice dell'Amministrazione Digitale (the Italian Digital Administration Code), together with the retention rules of Presidential Decree 633/1972 (the Italian VAT Decree). Retention must occur in a system of conservazione sostitutiva — a certified electronic archive that preserves the legal authenticity and integrity of documents over time.

Conservazione sostitutiva is not simply a matter of saving XML files on a server. The process requires that documents be stored by an accredited provider or in a system that meets the technical standards of the Agenzia per l'Italia Digitale (AgID), Italy's digital infrastructure authority. Documents must be sealed with qualified electronic signatures and timestamps at the moment of archiving. A foreign company that backs up its FatturaPA XML files in a generic cloud folder has not complied with conservazione sostitutiva.

The practical consequence of non-compliance with retention rules is that the Agenzia delle Entrate can disallow deductions for any period where documents cannot be produced in compliant form, even if the underlying transactions were genuine. The 10-year period is not negotiable.

The 2026 automated assessment risk and what it means for your compliance calendar

From January 2026, the Agenzia delle Entrate activates automated VAT assessment proceedings when an entity registered for partita IVA fails to file its annual VAT return. The mechanism is provided under the broader digital compliance architecture built through Law 111/2023 (the Italian Tax Reform Delegation) and subsequent implementing decrees. The system cross-references SDI transaction data against the annual return; material discrepancies trigger automated notices, and non-filing triggers assessment without manual intervention.

This is the point where SDI technical compliance and tax procedural risk converge. A foreign company that has been transmitting FatturaPA invoices through SDI but has not filed its annual Italian VAT return now faces automated assessment based on the SDI data the authority already holds. There is no longer any practical obscurity: SDI is the authority's live data feed.

Vigilantibus non dormientibus iura succurrunt — the law assists the watchful, not those who sleep on their rights. The adage applies here with particular force: the digital infrastructure that now surrounds the Italian VAT system leaves foreign operators very little margin for passive compliance.

As the jurist Friedrich Carl von Savigny observed in the context of legal systems confronting economic reality: forms are not mere technicalities; they are the guarantors of certainty in legal relationships. The FatturaPA format, and the controls now embedded in version 1.9.1, are precisely this kind of guarantee — but one that imposes costs on those who treat form as secondary to substance.

The practical takeaway is a compliance calendar with hard dates. Your ERP or invoicing software must have been updated to the v1.9.1 schema by 15 May 2026. Your accounts-payable process must now track Italian supplier invoices against the 90-day TD29 window. Your annual Italian VAT return must be filed on time to avoid automated assessment. And your document retention must occur in a certified conservazione sostitutiva system, not in a generic archive.

Foreign companies whose Italian operations are managed remotely, often through a part-time fiscal representative or an accounting firm that handles only tax returns, may find that none of these process-level controls exist in practice. The update to version 1.9.1 is the moment to audit the entire Italian compliance chain, not just the invoicing software.

Image prompt: A foreign business executive sits at a minimalist desk in a Milan office, studying two side-by-side screens: one shows a rejected FatturaPA XML validation error in red, the other an Italian tax authority compliance dashboard with green and amber indicators. The scene is lit with cool northern light from tall windows, evoking precision and urgency. Colour palette of slate blue, warm ivory and amber.

Image file: italy-e-invoicing-foreign-companies-sdi-2026-cover

JSON-LD:

LANGUAGE QA: The answer turns on one fact -> The answer depends on one fact · the position of a foreign company without a partita IVA is different -> A foreign company without a partita IVA is in a different position · statutory prescription -> statutory requirement / legal mandate · the mandate -> the SDI obligation / this requirement · triggers scrutiny under the automated assessment system -> attracts scrutiny from / flags the return for · their mandate must be current -> their authority / appointment must be up to date · accounts-pay -> accounts payable process · as consolidated in the Italian VAT framework -> as amended / as in force under

CHECK:
Law 205/2017 as basis for Italian e-invoicing mandate / EXISTS? Yes — confirmed via normattiva.it and widely documented / CONTENT MATCHES? Yes — mandate operative from 1 January 2019 for domestic B2B transactions.

SDI technical specifications versioning system / EXISTS? Yes — Agenzia delle Entrate publishes versioned technical specs for FatturaPA / CONTENT MATCHES? Yes — versioning system confirmed. Specific v1.9.1 effective 15 May 2026 with TD29 and 100+ controls: sourced from the article brief provided; TO VERIFY independently at Agenzia delle Entrate portal before publication.

TD29 document type / EXISTS? Yes — introduced per v1.9.1 per the brief. TO VERIFY: confirm TD29 specification text and 90-day window against the published v1.9.1 document at Agenzia delle Entrate.

TD17, TD18, TD19 document types / EXISTS? Yes — confirmed in Agenzia delle Entrate official documentation and widely documented in Italian tax practice / CONTENT MATCHES? Yes.

Legislative Decree 471/1997, Article 6(8) — penalty for missing invoice / EXISTS? Yes — confirmed via normattiva.it / CONTENT MATCHES? Yes — this provision establishes the buyer's liability and penalty equal to the tax amount.

Presidential Decree 633/1972 — Italian VAT Decree retention rules / EXISTS? Yes / CONTENT MATCHES? Yes — standard citation for Italian VAT documentary obligations.

Legislative Decree 39/2021, Article 8 — 10-year retention / EXISTS? Yes — D.Lgs. 39/2021 confirmed / CONTENT MATCHES? Partial — the brief cites this alongside the Codice dell'Amministrazione Digitale; the specific provision number for the 10-year FatturaPA retention should be verified against the published text before publication. TO VERIFY.

Law 111/2023 — Tax Reform Delegation / EXISTS? Yes — confirmed via Gazzetta Ufficiale and normattiva.it / CONTENT MATCHES? Yes — provides the legislative basis for the digital compliance and automated assessment architecture.

Latin maxim: Vigilantibus non dormientibus iura succurrunt — standard Roman law maxim, well-attested in legal literature. Not one of the forbidden phrases. CONFIRMED appropriate and non-trivial.

Savigny citation — well-established historical authority. Not unverifiable opinion. CONFIRMED.

OVERALL: AMBER — core legislative framework confirmed; v1.9.1 specifics (TD29, 90-day window, 100+ controls, 15 May 2026 effective date) sourced from the provided brief and should be cross-checked against the Agenzia delle Entrate SDI portal before publication; D.Lgs. 39/2021 Article 8 should be verified for precise provision number.

LOCAL NOTE:
1. Search intent targeted: informational, with strong transactional pull — a foreign company discovering it is non-compliant with v1.9.1 or TD29 is immediately ready to instruct Italian counsel.
2. Local-market framing: the contrast passage explicitly addresses common-law jurisdictions where invoicing format is commercial practice, not statutory mandate — this directly targets UK, Irish, US, Australian and Canadian readers whose instinct is that a PDF invoice is legally valid.
3. Italian terms kept untranslated and why: conservazione sostitutiva — kept because no English equivalent captures the legally certified nature of the archive; explained in plain language on first use. FatturaPA — kept as a proper technical name (the Agenzia delle Entrate uses it in English-language materials). intermediario fiscale — kept in italics with English explanation as it is a specific role in the Italian system with no direct common-law equivalent.