Compliance dates · 1 October 2026 · EU (Greece)
Greek B2B e-invoicing covers every remaining resident taxpayer from 1 October 2026
Phase two of mandatory B2B e-invoicing via myDATA starts on 1 October 2026 and covers all remaining resident taxpayers. The March 2026 phase took the first group, and this one takes the rest.
An adjustment period runs to 31 December 2026. The duty starts in October and the adjustment period sits behind it, closing at the end of the year. Phase one in March 2026 took the first group of resident taxpayers. Phase two closes the gap behind them.
Greek-established businesses outside the March phase
Every Greek-established business not already caught by the March 2026 phase, which means the whole SME base. A Greek micro-business is inside phase two the same as a mid-sized one.
Preparing the invoicing route
- Confirm whether your business was caught by the March 2026 phase or falls into phase two.
- Put a myDATA-capable B2B invoicing route in place for 1 October 2026.
- Test it on live invoices during the adjustment period rather than after it.
- Diarise 31 December 2026 as the point the adjustment period closes.
- Keep the invoices issued during the adjustment period alongside their myDATA confirmations.
No single instrument in the register covers Greek e-invoicing
The Greek mandate sits outside the register's 87 instruments. Your route in is the assessment, which maps every instrument that does apply to your business.
The free assessment tells you which of the 87 instruments apply to you. Start the free assessment.
Verified 19 August 2026.