The countdown to the mandatory implementation of electronic invoicing has begun. From Monday, 2 February 2026, all businesses operating in the Greek market with gross revenues exceeding €1 million for the 2023 tax year are required to issue electronic invoices for the sale of goods and the provision of services. A second phase will follow in October, when the obligation will be extended to businesses with lower gross revenues.

Gradually, therefore, the way invoices are issued by businesses and professionals is changing radically from this year onward, with the aim of curbing tax evasion and the issuance of fake invoices. The introduction of mandatory electronic invoicing is expected to offer significant benefits, such as:

• reduction of VAT losses and limitation of the issuance of fake tax documents
• significant facilitation for businesses in fulfilling their reporting obligations, thanks to the pre-filling of VAT returns and form E3
• enhancement of competitiveness and reduction of administrative costs for Greek businesses (cost of issuing, sending, and storing invoices, reduction of lost invoices, manual data entry errors, and disputes with counterparties)

What changes from tomorrow

Under the new system, businesses send their transaction data to a certified Provider, which issues the electronic invoice and simultaneously transmits it to the issuer, the recipient, and the myDATA platform of the Independent Authority for Public Revenue (AADE) in real time.

The first phase of mandatory electronic invoicing starts tomorrow and concerns businesses and professionals with high turnover.

Specifically:

• By Monday, 2 February, businesses with turnover exceeding €1 million must have signed a contract with an electronic invoicing Provider in order to install electronic invoicing systems.
• By 12 February, they must submit to myDATA the “Declaration of Commencement of Electronic Issuance of Documents.” This declaration is submitted either by the electronic invoicing provider contracted by the business, or by the business itself if it chooses to use the free timologio application of AADE.
• Until 31 March, a transitional period of gradual adjustment is provided. During this time, existing commercial or accounting systems and special entry forms may operate in parallel with the new electronic invoicing system. From 1 April, “traditional” systems are abolished and fully electronic invoicing is implemented.

The critical deadline: Provider declaration by 12/2

According to Article 6 of Decision A.1112/2025, the provider must submit the “Declaration of Commencement of Electronic Issuance of Documents” via the myAADE digital portal no later than ten days from the effective date of the contract with the business. The issuing entity (the business) is informed via posting in the e-notifications application and electronic notification, and may accept or reject the declaration within ten days. If the deadline passes without action, acceptance is presumed.

In practice, this ten-day period ends for everyone on 12 February (10 days after Monday, 2 February).

However, according to information from AADE, out of the 38,000 businesses required to comply, only 19,961 (53%) have completed the process. The remaining 18,000 businesses have less than ten days to check whether—and what—the provider they have contracted has declared on their behalf. AADE has already sent notifications regarding this pending issue to these businesses.

Among them, 3,300 businesses are already using a provider or the timologio or myDATAapp applications, but have not submitted the required declaration.

Nevertheless, the procedure described in Article 6 provides that if the provider does not submit the required declaration within the ten-day period, responsibility is transferred to the contracting Issuing Entity (i.e., the business itself), which is then obliged to submit the declaration within ten days after the provider’s deadline expires.

The declaration is mandatory, even if the business has already started issuing electronic invoices earlier. Any omission entails serious risk. From 13 February onward, invoices issued without a provider or outside the free timologio and myDATAapp applications may not be considered valid. Under the law, failure to issue invoices using one of the above two lawful methods is equivalent to non-issuance of an invoice.

This results in a fine equal to 50% of the VAT for each document identified by the tax authorities as not having been legally issued. Therefore, the obligation to submit the declaration is not merely “formal,” since any omission may endanger the viability of businesses, especially those with a high volume of transactions.

Phase B from 1 October with incentives

From 1 October 2026, mandatory implementation begins for the remaining businesses (with turnover below €1 million), with a transitional period until 31 December of the same year. This gradual transition aims at the smooth adaptation of the business community to the new regime.

For businesses and professionals in this category, significant tax incentives for early adoption are also provided.

Specifically, Phase B businesses that choose to sign a contract with a provider early and join electronic invoicing at least two months before the mandatory date (in practice, by 3 August) will benefit from:

• 100% increased depreciation for the purchase of equipment and software
• 100% increase in the deductible expense for invoicing services in the first year

That is, each such expense will be deductible at 200%.