E-invoicing in Greece is no longer an option for a few early adopters. Issuing electronic invoices for business to business transactions is becoming mandatory in two phases. The first phase started in 2026 for larger businesses and the second phase covers almost everyone else, including small businesses and self-employed professionals.
From 1 October 2026 the obligation extends to the remaining businesses. If you have not organised this yet, this guide explains what changes and what to do.
What e-invoicing actually is
An electronic invoice is not a PDF you send by email. It is an invoice in a structured data format, following the European standard, issued and transmitted through certified solutions and at the same time sent to the tax authority platform myDATA. In practice the tax authority sees the invoice at the moment it is issued.
Who is affected
- businesses and self-employed professionals issuing invoices to other businesses in Greece (B2B)
- businesses invoicing public sector bodies, where e-invoicing is already mandatory
If you only sell to consumers with retail receipts, this particular obligation does not apply to those transactions. As soon as you issue even one invoice to another business, however, you will need an e-invoicing solution. Transactions with businesses abroad follow their own rules and are worth checking separately.
What changes day to day
For the issuer
Invoices will no longer be written out of a paper book or a simple desktop program. They will be issued through a solution that supports e-invoicing, usually a certified e-invoicing provider, and will automatically receive a MARK reference from myDATA.
For the recipient
The business receiving the invoice must be able to receive it electronically and classify it correctly in its books. This is usually arranged together with the accountant.
Credit notes
If you sell on credit and often issue returns or discounts, credit notes are issued electronically too, linked to the original invoice.
Checklist: what to do now
- write down how you issue invoices today and how many you issue per month
- ask the provider of the software you already use whether it supports e-invoicing
- compare costs based on the number of invoices you actually issue
- check that your customers’ details, tax number and address, are correct
- tell your accountant which solution you chose, so it can be connected to your books
- run a test invoice before the obligation starts for you
How to choose a solution
Not every business needs the same program. A freelancer issuing a handful of invoices a month has very different needs from a wholesaler issuing hundreds. Before signing a contract, check:
- whether pricing is per invoice or a fixed monthly fee
- whether it connects to the cash register or commercial software you already have
- whether it works from a mobile phone when you are out of the office
- what support you get when something does not work
Because details and transition periods can change with new decisions from the tax authority, confirm the current position with your accountant before you commit.
Would you like help getting your business ready for e-invoicing? See our services or contact us.
For step-by-step instructions on the AADE and EFKA platforms, see our Useful guides.
Frequently asked questions
From when is e-invoicing mandatory for small businesses?
The second phase, covering the remaining businesses, starts on 1 October 2026. Check with your accountant whether a transition period applies to your case.
Does it apply to retail receipts issued to consumers?
The obligation concerns invoices between businesses (B2B). Retail receipts follow their own rules, such as the connection of cash registers with card terminals.
Can I keep sending invoices as PDF?
A PDF can still be sent as a copy, but where the obligation applies the invoice must be issued and transmitted in the way e-invoicing requires.
How does e-invoicing relate to myDATA?
The electronic invoice is transmitted to myDATA when it is issued and receives a MARK reference, so the data the tax authority sees matches your books.