Electronic Invoicing in San Marino: Mandatory for B2B Transactions Starting in 2027

San Marino is moving forward with the digitization of its tax processes by introducing mandatory electronic invoicing for domestic B2B transactions effective January 1st, 2027.

The new model is regulated by Delegated Decree No. 133 of September 4th, 2026, which establishes the general rules for the issuance and transmission of invoices in the exchange of goods and services between economic operators in San Marino.

The new regulation represents an evolution of the electronic invoicing system that San Marino has already been using for several years in its commercial relations with Italy. The HUB-SM infrastructure, which currently serves as a connection point with the Italian Sistema di Interscambio (SdI), will also play a central role in invoicing between companies within San Marino itself.

 When will electronic invoicing become mandatory in San Marino?

B2B electronic invoicing in San Marino will be mandatory as of January 1st, 2027, for businesses falling within the scope of the new regulations.

A transition period is established prior to this date:

• From October 1 to December 31st, 2026: voluntary use of electronic invoicing for domestic transactions.
• January 1st, 2027: The requirement takes effect for economic operators subject to the mandate.
• January 1st, 2028: Specific penalties for noncompliance begin to apply.

The mandatory implementation in 2027 had already been announced by the Government of San Marino in its 2026 Economic Program, which noted that the domestic electronic invoicing project was in the technological development phase following the regulatory and technical work carried out during 2024 and early 2025.

Who will be required to issue electronic invoices in San Marino?

Delegated Decree No. 133 mandates the use of electronic invoices for B2B transactions between entities in San Marino that hold an economic operator code.

However, the regulation provides an exception for operators who reported income of less than 100,000 euros during the previous year.

These entities may remain exempt from the requirement, although they will have the option to voluntarily adopt electronic invoicing.

How will B2B electronic invoicing work in San Marino?

The new system leverages the technological infrastructure that San Marino already uses to manage the exchange of electronic invoices with Italy.

Domestic electronic invoices must be prepared and transmitted electronically via HUB-SM to the Ufficio Tributario.

In simple terms, the new workflow will be:

San Marino Supplier → HUB-SM → Tax Office → San Marino Customer

HUB-SM will therefore be a central component of the system, responsible for receiving and processing invoices before they reach the recipient.

For each processed document, a HASH code will also be generated to uniquely identify the invoice and ensure its traceability within the system.

What happens if HUB-SM rejects an invoice?

One of the most important aspects of the regulation is that an electronic invoice rejected by HUB-SM is considered not to be not sent.

This means that simply generating or sending the invoice from the supplier’s system is not sufficient. The document must successfully pass the checks established by HUB-SM.

This principle is already part of how HUB-SM operates for electronic transactions between San Marino and Italy and is also incorporated into the new domestic model.

What happens if a company does not receive the electronic invoice?

The regulations also establish obligations for the recipient.

If two months have passed since the issuance deadline and the customer has still not received the corresponding electronic invoice, the customer must rectify the situation.

The purchaser or recipient will have an additional 30 days to prepare and electronically transmit a document through the system, following the rules specified in the Technical Implementing Regulation.

Timeline for Electronic Invoicing in San Marino

The evolution of the system can be summarized in four key dates:

• October 1st, 2021: The phased introduction of electronic invoicing begins for transactions between San Marino and Italy.
• July 1st, 2022: Electronic invoicing becomes mandatory for certain transactions between businesses in San Marino and Italy, with the exceptions provided for by the regulations.
• October 1st, 2026: The voluntary period for using electronic invoicing in domestic B2B transactions in San Marino begins.
• January 1st, 2027: Electronic invoicing becomes mandatory among economic operators in San Marino subject to the new regulation.
• January 1st, 2028: The specific penalties provided for in the new regulation take effect.