Greece Clarifies Declaration Rules for Timologio and myDATAapp Users
On September 22, 2026, the Independent Authority for Public Revenue (AADE) published clarifications on when businesses using its free Timologio and myDATAapp applications must file the “Declaration of Commencement of Electronic Issuance of Fiscal Documents.” The guidance accompanies the rollout of mandatory e-invoicing, which Greece extends to all remaining B2B taxpayers from October 1, 2026.
When the Declaration Has Been Required
Under the current regulatory framework (Decisions A.1128/2025 and A.1129/2025), the declaration is required in two situations:
- to benefit from the incentives for early adoption of e-invoicing under Article 71Θ(1) of the Income Tax Code, for as long as those incentives applied; and
- to allow in-scope entities to comply gradually by using existing invoicing methods in parallel with e-invoicing.
Who Must Submit the Declaration
From October 1, 2026, the declaration is required only from businesses with gross revenues of up to EUR 1,000,000 in the 2023 tax year that wish to use the adaptation period running from October 1, 2026, to December 31, 2026. During this period, such businesses may keep issuing invoices through their existing methods alongside e-invoicing. These businesses may submit the declaration until October 12, 2026.
Businesses that, from October 1, 2026, issue their invoices exclusively through Timologio or myDATAapp do not need to file the declaration.
Scope of the Clarification
The clarification applies only to declarations related to the use of Timologio and myDATAapp. It does not affect the separate declaration obligation for businesses using the services of an Electronic Invoicing Provider, as set out in AADE Decision A.1112/2025.
AADE also confirmed that mandatory e-invoicing does not change the obligations or issuance procedures for revenue documents in transactions with final consumers, i.e., retail (B2C) transactions.
Submission and Support
Where required, the declaration is filed through the myAADE digital portal (myaade.gov.gr), under Applications > Tax Services > myDATA > Declaration of electronic issuance of documents via a Provider, Self-Provider, or the Timologio application.
Taxpayers seeking further information can contact AADE’s my1521 service by phone at 1521 (free of charge, on working days from 7:00 to 20:00) or digitally at my1521, which is available 24/7.
There’s more you should know about e-invoicing in Greece – learn more about the new and upcoming regulations.
