Mandatory e-invoicing is entering its final implementation phase, as of October 1, 2026, when the measure will be extended to small businesses with annual turnover of up to €1 million. Following its rollout to large enterprises, the measure now covers virtually the entire market, significantly narrowing the margin for off-the-books transactions and phantom invoices — adding yet another digital tool to the Greek Independent Authority for Public Revenue’s (AADE) arsenal in the fight against tax evasion.
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From the date the measure takes effect, all invoices must be issued exclusively in electronic format — either through a certified electronic document issuance provider or via AADE’s free applications, “timologio” and “myDATAapp.” To ensure a smooth transition to the new regime, a three-month transitional period will be in place, running through the end of December.
E-invoicing applies to all business-to-business (B2B) transactions conducted within Greece, as well as to the sale of goods and provision of services to businesses established in third countries outside the European Union. By contrast, for transactions with businesses in EU member states, the use of electronic invoices remains optional for the time being. If a foreign client is unable or unwilling to receive an electronic invoice, the document may be transmitted through an alternative method in accordance with current procedures.
Steps businesses need to take
1. Choose a transmission channel: The business selects a modern invoicing software solution (ERP) and a certified provider, or opts for AADE’s free applications — timologio and myDATAapp.
2. Declare the transmission channel: Businesses must declare whether they are using a certified provider (YPAIES) or the “timologio” application. Selecting the “timologio” option also covers the use of AADE’s myDATAapp.
3. Issue and transmit digital documents: Invoices are issued electronically and automatically transmitted to the myDATA platform, where they receive the mandatory Unique Registration Number (MARK).
Discounts and tax incentives
Businesses that voluntarily adopt e-invoicing as their exclusive method of issuing documents before the mandatory deadline becomes effective will be eligible for the following incentives:
- The cost of initially acquiring the hardware and software required to implement e-invoicing is fully deductible, with an additional 100% uplift applied to the expense.
- The costs associated with generating, transmitting, and electronically archiving e-invoices during the first 12 months of issuing sales documents through the e-invoicing system are deductible from gross business income, with a 100% uplift applied in the year the expense is incurred.
These incentives are available to businesses provided that:
- A declaration has been submitted for the use of e-invoicing — either through a certified provider’s services or through AADE’s document issuance and transmission application — no later than 2 months before the mandatory e-invoicing obligation takes effect (i.e., by August 3, 2026) for the sale of goods and provision of services.
- The actual use of e-invoicing begins within that same period.
Penalties for non-compliance
Failure to issue an electronic invoice is treated as a failure to issue any invoice at all, with fines reaching up to €2,500 per violation or audit, depending on the business’s accounting system and the nature of the transaction. Specifically:
VAT-liable transactions: A penalty equal to 50% of the tax that would have arisen from the unissued document — or of the discrepancy — is imposed. The minimum cumulative fine per tax audit is €250 for businesses using single-entry bookkeeping and €500 for those using double-entry bookkeeping.
Non-VAT transactions: A fine of €500 per tax audit applies to businesses using single-entry bookkeeping, and €1,000 per audit for those using double-entry bookkeeping.
Omission or inaccurate submission of data: A standalone fine of €2,500 is imposed on any person who fails to submit — or submits inaccurate — data relating to their specific obligations within the system.
