Greece Delayed Mandatory B2B E-Invoicing and Introduced Transition Period

Greece has slightly postponed mandatory B2B e-invoicing for large businesses to March 2, 2026, introducing a transition period until May 3, 2026 to allow system adaptation. While penalties are deferred until the end of this period, non-compliance will still be strictly sanctioned as if no invoice was issued.

Greece has postponed the start of mandatory B2B e-invoicing. Instead of beginning in February 2026, the obligation started on March 2, 2026.

The delay applies to large businesses that had annual revenues above €1 million in 2023. These companies are part of the first phase of the national e-invoicing rollout.

New timeline:

1. March 2, 2026 → Mandatory e-invoicing officially starts
2. March 2 – May 3, 2026 → Transition period

During this transition period, businesses can:

• Continue using their existing ERP/accounting systems, or
• Use the Tax Authority’s (AADE) free tools while preparing their systems.

Businesses must issue e-invoices using one of the following:

1. An approved e-invoicing provider (ΥΠΑΗΕΣ),
2. AADE’s free tools (timologio app or myDATAapp).

To benefit from the transition period and avoid penalties, companies had to:

• Submit a formal declaration that they are starting e-invoicing,
• Set the start date as March 2, 2026.

Penalties are still strict, but they will apply later than planned:

• Start of penalties: May 3, 2026 (instead of April 1).

If a company does not issue compliant e-invoices:

• It is treated as if no invoice was issued at all.

Fines include:

1. 50% of VAT amount (for VAT transactions),
2. €500 or €1,000 fines depending on accounting method (non-VAT cases).

Greece has given businesses extra time to prepare, but the obligation remains strict. This is not a delay of the reform, but a short transition period to allow smoother implementation.