Greece postpones mandatory B2B e-invoicing for large businesses
On 18 February 2026, the Greek Ministry of National Economy & Finance and the Independent Authority for Public Revenue, AADE, announced a one-month extension of the mandatory B2B e-invoicing go-live for large businesses.
The original start date of 2 February 2026 has been moved to 2 March 2026. The gradual implementation window will now run from 2 March to 3 May 2026. Previously, this window was set from 2 February to 31 March 2026.
The extension applies to Phase 1 businesses with gross revenues exceeding €1,000,000 in fiscal year 2023.
The obligation itself does not change. Only the timeline has been adjusted.
A timing shift within Greece’s digital tax framework
Mandatory B2B e-invoicing is part of Greece’s broader digital reporting strategy, closely connected to the myDATA platform.
Large enterprises are the first group required to comply. The phased structure remains intact. The authorities have simply provided additional time for technical and operational readiness.
This pattern is not unique. Across Europe, authorities are refining timelines and technical frameworks as implementation approaches. A comparable example is Croatia, which confirmed mandatory e-invoicing from 2026 and clarified how its system will operate in practice. Earlier developments are outlined in:
Croatia confirms mandatory e-invoicing from 2026
Croatia clarifies e-invoicing system status
These updates show a broader regional shift toward structured electronic transaction control.
Transitional period until May 2026
Between 2 March and 3 May 2026, businesses may:
- Continue operating existing ERP or accounting systems in parallel with compliant electronic invoicing
- Use AADE’s dedicated entry form
- Complete technical integration and process adjustments
This period functions as a controlled transition window. It does not suspend the requirement to move to compliant electronic issuance.
After 3 May 2026, enforcement begins.
Declaration required to avoid penalties
To benefit from the transition period and avoid penalties, companies must submit on time:
- A Declaration of Commencement of Electronic Document Issuance
- A Declaration of Use of the Timologio free application
The effective start date must be set to 2 March 2026, in line with Article 6 of Ministerial Decision 1112/2025.
Without this formal declaration, the grace period does not apply.
Two compliance routes remain available
Large businesses can comply by:
- Selecting an accredited e-invoicing service provider, Y.PA.H.E.S.
- Using AADE’s free tools, including the Timologio application and the myDATAapp mobile application
For ERP-driven organisations, this choice impacts integration design, internal controls and data consistency with myDATA reporting.
In Croatia, similar discussions are taking place around fiscalisation and structured reporting under Fiscalization 2.0, where invoice data transmission and validation are also central elements. More context is available here:
Croatia e-invoicing Fiscalization 2.0 update
The underlying trend is clear. E-invoicing is increasingly embedded in real-time or near real-time tax control frameworks.
Enforcement date moves, penalties unchanged
The penalty framework itself has not been amended.
Penalties for non-compliance will now apply from 3 May 2026 instead of 1 April 2026. This effectively grants one additional month before enforcement starts.
Operational implications for finance teams
Although the extension offers additional time, the structural change remains significant.
Finance teams should use this period to:
- Validate ERP integration with AADE or the selected provider
- Test structured invoice generation and transmission flows
- Align invoice data with myDATA reporting requirements
- Define monitoring and exception handling procedures
- Clarify ownership between finance and IT
Changes companies need to implement
- Update internal timelines to reflect the 2 March 2026 go-live
- Submit the required declaration with the correct effective date
- Finalise system configuration and technical integration
- Perform end-to-end testing of issuance and reporting
- Document control procedures and compliance monitoring
The extension creates room for structured preparation. It does not reduce compliance pressure.
