From 1 October 2026, electronic invoicing becomes mandatory for all businesses in Greece for their domestic B2B transactions. Large businesses, those with revenue above 1 million euros in 2023, have already been issuing e-invoices since March 2026. Now it is the turn of everyone else.
If your invoices are still issued from a simple invoicing program or on paper, this is the moment to organise the change. Below you will find what the new obligation means and a practical checklist.
What changes
Every B2B invoice between Greek businesses must be issued in a structured electronic format and transmitted in real time to the myDATA platform of the Independent Authority for Public Revenue (AADE). A PDF sent by email is no longer enough.
Businesses can choose between three ways: a certified e-invoicing provider, or the free AADE applications timologio and myDATAapp. The chosen method must be declared to AADE.
Key dates
- 2 March 2026: start for large businesses
- 1 October 2026: start for all other businesses
- Until 31 December 2026: transition period for the second phase
Non-compliance can be costly: for transactions subject to VAT, the fine can reach 50% of the VAT amount of the invoice.
Practical checklist
- Check with your accountant which transactions are affected
- Choose a transmission method: certified provider or AADE application
- Make sure your ERP, e-shop or invoicing software can connect to a provider
- Clean up your customer master data, especially VAT numbers
- Run test invoices before the deadline
- Train the people who issue invoices
Where most businesses get stuck
The hardest part is usually not the law, but the software. Many businesses issue invoices from an e-shop, a custom application or an older ERP that was never designed to talk to a provider. In these cases, a small integration can automate the whole process and remove manual double entry.
At Webrise we have many years of experience with myDATA, ERP and e-shop integrations. If you want your invoicing to run automatically before the deadline, get in touch with us.
This article is for general information and does not replace advice from your accountant or tax advisor.
