Greece Prepares for Wider Mandatory E-Invoicing from October 2026

Greek businesses are entering the final preparation period for the next stage of mandatory electronic invoicing.

From October 1, 2026, businesses not already covered by the first implementation phase will be required to issue invoices electronically for applicable business-to-business transactions. Larger businesses with gross revenues exceeding €1 million were already brought into the system from March 2, 2026.

Businesses must choose how they will issue and transmit their electronic invoices. They may use a certified electronic invoicing provider or the Tax Authority’s free timologio and myDATAapp applications.

They must also submit the appropriate declaration to the Tax Authority, identifying the invoicing method they will use. For businesses entering the second phase, the declared starting date must be no later than October 1, 2026.

Invoices issued through these systems will be transmitted automatically to the Tax Authority’s myDATA platform and will receive a unique registration number known as a MARK.

However, the change will not happen completely overnight. Businesses that submit the required declaration on time may continue using existing invoicing methods alongside electronic invoicing during a transitional period from October 1 to December 31, 2026. After this period, electronic invoicing will become the exclusive method for the transactions covered by the rules.

A separate deadline applies to digital documents used for transporting goods. From October 12, 2026, the second phase of Greece’s digital goods-movement system will become mandatory, covering procedures such as loading, transfers, receipt of goods and quantity and quality checks.

The reforms are intended to give the Tax Authority real-time access to transaction and goods-movement information, reduce manual reporting and strengthen controls against tax evasion.