Mandatory E-Invoicing in Greece: What Businesses Need to Know

In recent years, Greece has extensively digitized its financial and tax infrastructure. With myDATA, the Greek tax authority (AADE) already has a system in place that allows businesses to report invoice and accounting data digitally. In 2026, mandatory electronic B2B invoicing will be added to this system.

The implementation will take place in two phases. For businesses with gross revenue exceeding €1 million—based on the tax return for the 2023 tax year—mandatory electronic invoicing has been in effect since March 2, 2026.

For all other companies, e-invoicing will become mandatory as of October 1, 2026. For this second group, a transition period will be in effect through December 31, 2026, during which the new procedure can be gradually implemented under certain conditions.

Starting in 2027, the B2B requirement will therefore, in principle, apply broadly to businesses subject to Greek Accounting Standards.

Which transactions are covered by the requirement?

The Greek requirement applies primarily to sales of goods and services between businesses in Greece. For such domestic B2B transactions, the supplier must issue an electronic invoice, and the customer is required to accept the electronic invoice.

Notably, the requirement also applies to invoices issued by Greek companies to business customers outside the European Union. If the foreign customer is unable or unwilling to receive the electronic invoice, the supplier may also make the invoice available through an alternative channel.

For sales to businesses in other EU member states, mandatory Greek e-invoicing does not apply for the time being. The use of e-invoices for these transactions is voluntary. Starting in 2030, however, such cross-border B2B transactions will fall within the scope of the European Digital Reporting Requirements (ViDA).

A different rule also applies to incoming transactions from abroad. A Greek business is not similarly required to accept an electronic invoice from a foreign supplier using the domestic Greek model.

What does Greece consider an e-invoice?

An electronic invoice is more than just a digitally readable document. A PDF sent via email is therefore not sufficient to comply with the new Greek B2B requirement.

The invoice must be issued electronically via a method authorized by AADE, and the data must be automatically transmitted to myDATA.

Greece has based its data model for electronic invoices on the European standard EN 16931. Additionally, the semantic structure of the invoice aligns with the business rules of the Peppol Core Invoice Usage Specification.

As a result, data such as supplier, customer, invoice lines, VAT, amounts, and payment information are recorded in a structured format that can be automatically processed by software.

What is myDATA?

myDATA stands for my Digital Accounting and Tax Application. It is the Greek tax authority AADE’s digital platform for electronic bookkeeping and tax reporting.

Through myDATA, data from income and expense documents is recorded electronically. Transactions are also classified for tax purposes, and the data can be used for VAT returns and other tax obligations, among other things.

myDATA already existed before the introduction of mandatory B2B e-invoicing. Businesses were therefore already required to submit invoice data digitally to AADE. With the new e-invoicing requirement, invoice exchange and tax reporting are linked much more directly.

When an electronic invoice is issued via a certified provider, the relevant invoice data is automatically sent to myDATA in real time. After successful processing, the invoice receives a unique registration reference, the MARK (Unique Registration Number).

How can businesses issue e-invoices?

Greece has two main methods for mandatory e-invoicing.

The first is the use of a certified Electronic Invoicing Service Provider. This provider must be approved by AADE and uses certified software for this purpose. The provider handles the electronic issuance, authentication, and real-time transmission of the invoice data to myDATA.

For larger companies, this service is typically integrated with the existing ERP or invoicing system. The invoice is then generated from the ERP, but the mandatory electronic issuance and communication with AADE take place via the certified provider.

An important distinction is that a standard ERP system, on its own, does not qualify as an approved method for issuing the mandatory e-invoice. However, the ERP system can serve as the source of the data and be integrated with a certified provider.

The second option is to use AADE’s free applications:

• timologio for desktop use;
• myDATAapp for mobile devices.

These applications are primarily intended for smaller organizations and self-employed individuals who do not need a comprehensive integrated invoicing environment.

How does e-invoicing via a provider work?

When using a certified provider, the invoicing process generally proceeds as follows:

1. The supplier creates the invoice from the ERP or invoicing system.
2. The data is submitted to the certified e-invoicing provider.
3. The provider verifies, authenticates, and issues the electronic invoice.
4. The relevant invoice data is automatically sent to myDATA in real time.
5. myDATA performs checks and assigns a MARK to the invoice.
6. The electronic invoice is made available to the customer.
7. The status and tax processing can then be incorporated into the financial records.

The technical specifications also allow for various representations to be retrieved from the electronic invoice, including a readable PDF, the detailed myDATA format, and a version based on EN 16931.

This allows the same invoice to be viewed by people as well as processed directly by financial systems.

What is the role of real-time VAT reporting?

Greece differs from several other European countries in that transactional tax reporting already existed before the general B2B e-invoicing requirement was introduced.

Invoice data is already submitted electronically to AADE via myDATA. When using an e-invoicing provider, the transmission of outgoing invoice data occurs automatically and in real time after the invoice is issued.

As a result, the tax authority quickly has access to detailed information about business transactions. This data can be used to cross-check the customer’s records, conduct tax audits, and further automate tax returns.

Greece is thus a clear example of the shift from traditional periodic VAT audits to transactional VAT compliance. E-invoicing becomes part of the same data chain that the tax authority uses for reporting and auditing.

E-invoicing and myDATA are not the same

Although both systems are closely linked, e-invoicing and myDATA reporting should not be considered the same thing.

myDATA is, first and foremost, the AADE’s tax data and reporting environment. Data that does not originate from a mandatory electronic invoice can also be processed within myDATA.

E-invoicing goes a step further: the invoice itself is issued electronically according to the prescribed method, and the tax data is automatically transmitted to myDATA as part of that process.

A company cannot, therefore, comply with the B2B e-invoicing requirement by simply reporting invoice data to myDATA from its ERP system. For mandatory electronic issuance, a certified provider or AADE’s applications must be used.

What role does Peppol play in Greece?

Peppol plays an important role in Greece, particularly in electronic invoicing to the public sector.

For B2G transactions, structured electronic invoices are sent via certified service providers and the Peppol network to the Greek government’s National Interoperability Center. The invoices are based on EN 16931 and the relevant Greek Peppol specifications.

For regular domestic B2B e-invoicing, however, Peppol is not the mandatory exchange network in the same way as it is, for example, in Belgium. The core of the Greek B2B model consists of certified e-invoicing providers or the AADE applications, linked to myDATA.

An international e-invoicing solution that supports Peppol therefore requires additional local functionality for Greece to comply with B2B tax obligations.

E-invoicing to the Greek government

Greece introduced mandatory e-invoicing to the government earlier than the general B2B requirement.

The implementation of B2G e-invoicing took place in phases for various categories of government organizations and public contracts. Since 2025, electronic invoicing has been widely mandatory for suppliers to the Greek public sector.

B2G invoices are structured in accordance with the European standard EN 16931 and routed to the relevant government agency via Peppol and the National Interoperability Center.

Suppliers can use a certified provider for this purpose. Since 2025, AADE has also offered “timologio B2G,” a public application that allows electronic invoices to be issued to government organizations even without a commercial provider.

International Transactions

The handling of international transactions is a notable feature of the Greek model.

For a Greek company selling goods or services to a business customer in a third country outside the European Union, the issuance of the invoice is, in principle, subject to the Greek e-invoicing requirement.

If the foreign customer is not technically connected to the Greek system or does not accept the electronic invoice, the invoice may also be made available to the customer by other means. The tax-related electronic issuance in Greece remains decisive in this regard.

For transactions with business customers in other EU member states, electronic invoicing is still voluntary under the current national regulations.

This will change at the European level as of July 1, 2030. At that time, ViDA will introduce mandatory electronic invoicing and Digital Reporting Requirements for relevant cross-border B2B transactions within the EU.

Penalties for Non-Compliance

Failure to correctly apply mandatory e-invoicing is treated very seriously by the tax authorities in Greece.

If a company fails to issue a valid electronic invoice for a transaction for which electronic invoicing is mandatory, this is treated as a failure to issue an invoice. The penalties set forth in the Greek Tax Procedure Code may then apply.

For organizations, this means that it is not only the technical ability to generate an e-invoice that matters. The proper selection of transactions, real-time processing, integration with myDATA, and handling of any errors must also be an integral part of the invoicing process.

What does ViDA have to do with Greece?

The Greek B2B requirement is a national e-invoicing mandate. It is therefore not the European e-invoicing requirement under “VAT in the Digital Age.”

However, since April 2025, ViDA has made it easier for EU member states to implement mandatory domestic e-invoicing. Greece has used this opportunity to further expand its existing myDATA infrastructure to include mandatory electronic invoicing.

Starting July 1, 2030, the European Digital Reporting Requirements for relevant cross-border B2B transactions will be added to this. For these transactions, e-invoicing will serve as the basis for harmonized digital VAT reporting within the EU.

Greece has also had a national real-time transaction reporting system in place via myDATA for some time. Under ViDA, national digital reporting systems must ultimately align with the European model and the associated standards.

For international organizations, this means they must simultaneously take into account both the current Greek domestic rules and the European model that will apply to cross-border transactions starting in 2030.

The Greek Roadmap for E-Invoicing

The key steps are:

• 2020: Greece introduces myDATA and lays the technical foundation for digital tax reporting and electronic invoicing.
• 2022–2024: Digital reporting via myDATA is further expanded, and real-time transmission of invoice data becomes increasingly important.
• 2024–2025: Mandatory B2G e-invoicing is phased in across the Greek public sector.
• September 1, 2025: E-invoicing becomes widely mandatory for relevant expenditures within General Government.
• March 2, 2026: Mandatory B2B e-invoicing begins for businesses with gross revenue exceeding €1 million, based on the 2023 tax year.
• October 1, 2026: The B2B requirement will be extended to all other businesses.
• October 1 – December 31, 2026: A phased implementation period applies to the second group, subject to certain conditions.
• January 1, 2027: The transition period ends, and the B2B requirement generally applies to all businesses.
• July 1, 2030: ViDA’s European Digital Reporting Requirements will apply to relevant cross-border B2B transactions.
• No later than January 1, 2035: National real-time transaction reporting systems must be aligned with the European ViDA model.

What does this mean for organizations?

For organizations with a Greek entity, the main change in 2026 will be in the relationship between the existing ERP, invoicing, and tax reporting processes. Being able to report data directly to myDATA will no longer be sufficient to issue all B2B invoices.

The organization must use a certified e-invoicing provider or AADE’s applications. For larger companies, this typically means that the ERP system will be integrated with a provider that handles electronic issuance, validation, authentication, and real-time communication with myDATA.

Greece thus demonstrates once again how different national e-invoicing models can be within Europe. Belgium uses Peppol as its central B2B infrastructure; France works with accredited platforms; Poland uses KSeF; Italy uses SdI; Romania uses RO e-Factura; and Greece combines certified providers with real-time reporting to myDATA.

For international organizations, this requires an e-invoicing infrastructure capable of translating the same financial data into various national formats, exchange models, and tax reporting requirements.