Greece embraces the digital future with mandatory B2B e-invoicing legislation

^{This article was last updated on 16 September 2025 to reflect the latest communicated implementation timeline for mandatory B2B e-invoicing according to the press release from the Greek AADE.}

Greece is taking a major digital leap forward: On 25 July 2025, the Greek Parliament officially adopted legislation that, among other provisions, will make electronic invoicing mandatory for business-to-business (B2B) transactions. Following this, on 16 September 2025, the Greek Independent Authority for Public Revenue (IAPR or AADE, Ανεξάρτητη Αρχή Δημοσίων Εσόδων, commonly abbreviated “ΑΑΔΕ” in Greek) issued a press release detailing the implementation timeline, starting as soon as February 2026. This shift will significantly modernise the country’s financial and tax reporting systems, so businesses should pay close attention.

Titled the National Customs Code and other provisions – Pension provisions, the new law (Law 5222/2025, published in Government Gazette ΦΕΚ Α΄ 134/28.7.2025), among others, amends Article 14 of Law 4308/2014 (the “Greek GAAP”), laying the foundation for a comprehensive e-invoicing regime in line with European standards.

Beyond just Tech: The digital transformation of B2B transactions, a game changer for Greek businesses

Electronic invoicing (e-invoicing) is more than a technological update - it's a systemic transformation. For businesses in Greece and those doing business with Greek companies, this change signals the beginning of a new era of digital compliance, efficiency, and transparency.

This shift is expected to streamline operations, reduce administrative burdens, and enhance the overall integrity of financial transactions, aligning Greece with broader European digital initiatives and strengthening its position in the global digital economy.

Let's take a closer look at what this means for businesses.

What’s in scope?

The new mandatory e-invoicing requirement applies to a wide range of business transactions for entities operating under Law 4308/2014 (the "Greek GAAP"), specifically those in points a), b) and c) of Article 14(1) of Greek GAAP, as amended, i.e.:

1. Domestic B2B transactions: This covers all sales of goods and provision of services conducted within Greek territory between businesses adhering to Greek accounting standards.

2. Cross-border transactions with non-EU entities: Invoicing for sales of goods or services to foreign entities based outside the European Union, with specific exclusion of retail transactions. For these foreign recipients outside the EU, alternative exchange mechanisms remain acceptable, but only on the receiving end. Greek businesses must still issue the invoice electronically.

3. Public sector transactions: This encompasses transactions related to public contracts and the billing of various expenditures to the General Government, unless other special provisions explicitly apply.

Additionally, the e-invoicing obligation extends to transactions involving parties not liable to issue an invoice, those who refuse to issue an invoice, or cases where a “clearance note” (σημείωμα εκκαθάρισης) is generated.

Crucially, all invoices within the mandatory scope must be issued electronically — no paper or PDFs allowed — and must conform to the European e-invoicing standard (EN).

It’s worth noting that, beyond the mandatory scope outlined, businesses have the option to voluntarily adopt e-invoicing for a wider range of transactions, leveraging its benefits for increased efficiency and transparency across their operations.

Greece’s e-invoicing infrastructure

For the transactions listed in Article 14(1) as outlined above, the authenticity and integrity of e-invoices must be ensured exclusively via one of two approved channels:

1. Certified e-invoicing providers (Υπηρεσίες Παρόχων Ηλεκτρονικής Έκδοσης Στοιχείων, or short Υ.ΠΑ.Η.Ε.Σ.), or

2. IAPR (Independent Authority for Public Revenue) - Ανεξάρτητη Αρχή Δημοσίων Εσόδων (ΑΑΔΕ) - the Greek national tax authority’s own issuing and transmission application, such as the free Timologio application and the free myDATAapp for mobile devices, which offer an equivalent solution and cover, at no cost, the issuance of electronic invoices related to public contracts.

For e-invoices issued outside the mandatory scope as detailed above, the authenticity of origin and integrity of content can be ensured using the same two channels, or in addition, any of the following methods: an advanced electronic signature based on a qualified certificate; Electronic Data Interchange (EDI) meeting EU Directive requirements; or through Tax Electronic Mechanisms (ΦΗΜ) (such as certified cash registers).

The road ahead: What comes next?

While the law was passed in July 2025, the implementation details have now been clarified by the AADE in a press release on 16 September 2025. Accordingly, mandatory B2B e-invoicing will be implemented in two periods:

1. Period A - large businesses (with gross revenues exceeding € 1 million for the tax year 2023):

   • 2 February 2026: Mandatory application begins.

   • From 2 February to 31 March 2026, electronic invoicing will be implemented alongside business management programmes (e.g. commercial, accounting or ERP systems) or a special registration form.

   • Businesses obliged to do so must submit either a Declaration of Commencement of Electronic Issuance of Data or a Declaration of Use of the Timologio Application - AADE’s free web tool for creating and transmitting compliant e-invoices - and must start issuing electronic invoices within this quarter.

2. Period B - other businesses:

   • 1 October 2026: Mandatory application begins.

   • From 1 October to 31 December 2026: Gradual adjustment period.

This means that the legal foundation for mandatory B2B e-invoicing is now in place under Law 5222/2025, and the “go-live” dates and phased implementation plan have been officially announced.

Going forward, businesses can expect future regulations that will cover:

• Invoice format and structure,

• System interoperability, and

• Roles and responsibilities of certified providers.

Importantly, transitional incentives, as detailed below, remain in place for early adopters. Businesses that begin using certified e-invoicing solutions ahead of the mandate may qualify for enhanced tax deductions.

The move toward mandatory e-invoicing is part of a broader push across the EU to modernise tax systems and reduce VAT fraud. For Greek companies, this isn’t just a compliance issue; it’s a strategic opportunity.

Seize the opportunity: Act now and unlock early adopter incentives

While the mandatory timelines are now clear, businesses should also be aware of the substantial financial incentives available for early adoption, offering a strategic advantage beyond mere compliance. The law provides specific, time-limited tax deduction benefits for entities that opt into e-invoicing before it becomes mandatory. By decision of the Governor of AADE, Giorgos Pitsilis, businesses that implement e-invoicing two months earlier than their respective deadline (i.e., until 1 December 2025 for Period A businesses and until 3 August 2026 for Period B businesses) will benefit from:

• Full depreciation, plus 100% of the cost of technical equipment and software, is permitted in the year of purchase.

• For the first 12 months after issuance, a 100% mark-up on the cost of producing, transmitting and electronically filing e-invoices is permitted.

These deductions apply to certain taxable income, with defined percentages and timeframes, as detailed in the articles on “φορολογικά κίνητρα” (tax incentives)  in the gazette.

In addition, early adopters will reap the many general business benefits offered by e-invoicing, such as:

• Streamlined operations with reduced paperwork and processing time.

• Faster payments and improved cash flow.

• Easier auditability and alignment with future EU-wide reporting obligations (e.g., ViDA - VAT in the Digital Age).

The bottom line

Greece’s adoption of mandatory B2B e-invoicing is a landmark moment, and one that will fundamentally reshape how businesses issue, transmit, and archive invoices. While the details are still unfolding, it’s clear that the digital transition is no longer optional.

Businesses operating in Greece should begin preparing now: Reviewing their current invoicing systems, evaluating certified providers, and consulting with legal and tax advisors.