Mandatory e-invoicing in Greece from 1 October 2026: deadlines, penalties and what to do now
From 1 October 2026, e-invoicing is mandatory for every business in Greece. Here are the dates that matter, why your ERP is no longer enough on its own, what the penalties are and the one condition attached to the transitional period.
From 1 October 2026, every B2B invoice in Greece is issued electronically and only through a certified YPAHES provider. Businesses with gross revenue above €1,000,000 in the 2023 financial year have been in scope since 2 March 2026. Now everyone else follows, roughly 1.3 million businesses.
One number shows where the market actually is: fewer than 145,000 VAT numbers have filed the declaration with AADE for their B2B transactions. About 1 in 10. If you are among the other 9, here is the full timeline and the decisions you need to make over the next two months.
Your ERP or commercial software is no longer enough
This is the point that catches most businesses out, which is why it comes first.
AADE has stated it explicitly: business management software (commercial, accounting or ERP) is not an accepted method of issuing invoices. If you currently issue invoices from your ERP and transmit them to myDATA through an interface, from October that channel no longer covers your obligation for issuing.
Issuing goes through a Provider of Electronic Document Issuance (YPAHES), meaning licensed software that authenticates and transmits the document.
Your ERP does not go away. It simply stops being the point of issue and becomes the system that feeds the provider, usually through an API.
The dates that matter
| Date | What applies |
|---|---|
| 2 March 2026 | Obligation for businesses with gross revenue above €1,000,000 (2023 financial year). Already in force. |
| 3 August 2026 | The window for the article 71Θ tax incentives closed. |
| 1 October 2026 | The obligation takes effect for every remaining business. |
| 12 October 2026 | Phase B for digital delivery documents. |
| 31 December 2026 | The transitional period ends. From 1 January 2027 there is no other channel. |
3 August 2026: the tax incentive window closed
The article 71Θ incentives required both the declaration and the start of exclusive issuing through a provider no later than 2 months before the mandate took effect. Chambers of commerce and industry bodies have asked for an extension, but nothing has been legislated. What the incentives actually covered is explained in our guide to the benefits of e-invoicing.
1 October 2026: the obligation takes effect
The declaration naming your provider must be filed on time, with a start date no later than 1 October 2026. In practice that means choosing a provider and completing the integration during September.
12 October 2026: Phase B for delivery documents
Digital monitoring of loading, transhipment and receipt becomes mandatory. The aggregate delivery note may still be issued on paper up to and including 11 October 2026.
The transitional period exists, but it has a condition
Between 1 October and 31 December 2026 you may meet the obligation gradually, using the other issuing and transmission methods in parallel.
This option is not automatic. It applies on condition that a Declaration of Commencement of Electronic Issuance has been filed on time, with a start date no later than 1 October 2026.
Put simply: file it and you gain three months of orderly adjustment. Skip it and you are out of compliance from 1 October, with no safety net.
Who files the declaration when you choose a provider
There is an important detail here that saves you work. When you contract with a provider, the provider files the declaration, through the myAADE portal, no later than 10 days from the date the contract takes effect.
You are notified through myAADE e-notifications and by email, and you have 10 days to accept or reject it. If that deadline passes with no action, the declaration is presumed accepted. If the provider fails to file on time, the obligation passes to you, within 10 days of their deadline expiring. The steps with screenshots are in our guide to the YPAHES provider declaration.
What the penalties are
Failure to issue an electronic invoice is treated as failure to issue an invoice, under the penalties of the Greek Tax Procedure Code:
| Breach | Single-entry books | Double-entry books |
|---|---|---|
| VAT transactions | 50% of the VAT due, minimum €250 | 50% of the VAT due, minimum €500 |
| Repeat offence | 100% of the VAT due, minimum €500 | 100% of the VAT due, minimum €1,000 |
| Moving goods without delivery documents | €5,000 per tax audit | €10,000 per tax audit |
And a trap for anyone who made the incentive deadline: the benefits are withdrawn if, before the mandate takes effect, an invoice is issued without using the provider, despite the declaration having been filed. One forgotten handwritten invoice in September can cancel the uplift.
Digital delivery documents, from 12 October 2026
Phase A, issuing and transmitting delivery documents, has applied since 1 December 2025. Phase B becomes mandatory on 12 October 2026 and covers loading, transhipment and receipt, with QR marking so goods can be tracked in real time. If you issue delivery notes, this date concerns you separately from 1 October.
Transmission windows:
| Case | Transmission window |
|---|---|
| Dispatch of stock | Before movement begins |
| Receipt of stock | In real time, once receipt is complete |
| Discrepancies (surplus or shortfall) | Within 15 days of receipt |
| Receipt from abroad | Within 5 days of receipt |
If connectivity is lost, the document is issued as normal carrying a distinct loss-of-connection marker, and is transmitted once the connection is restored, no later than one day afterwards.
Watch this one, because it concerns your relationship with your suppliers: after Phase B, receiving goods presupposes a digital delivery document. If a supplier has not adapted, their problem becomes yours.
What you gain beyond compliance
Compliance is the floor. The same connection, done properly, also gives you the following:
- Issuing with no human in the loop. When documents originate in an eshop, ERP, CRM, booking or subscription system, they are issued through the API at the moment of the transaction.
- Customers and suppliers without data entry. They are created automatically from the myDATA connection, and a new customer is added by VAT number.
- A real-time financial picture. Customer statements and balances, receipts, payments and expenses, from the same data you issue.
- One place for every document type. Wholesale, retail, credit notes, delivery notes, public-sector invoices, POS.
- Responsibility for authentication and transmission to AADE sits with the provider, as does safeguarding the data and the authentication credentials. That does not release you from your own separate obligation to retain your accounting records.
What to do this month
The migration will happen all at once in September. That means queues at providers, delays on integrations and almost no time to test. Five things, in this order:
- Map where every document is issued from today. ERP, commercial software, eshop, Excel, a paper book. Anything that issues a B2B invoice goes on the list.
- Measure your annual volume. That number decides whether you issue through the API or from inside the application.
- Choose a provider and sign. The declaration requires a contract in force, and the provider then has 10 days to file it.
- Test on staging before October. Every document type you issue, once, end to end.
- Check your suppliers on delivery documents, with 12 October as the horizon.
Where Wrapp fits
Wrapp is a certified YPAHES provider. Documents are issued and transmitted in real time, either from the application or through a REST API when issuing originates in your own system.
- Full document coverage: invoices, retail receipts, credit notes, delivery notes and public-sector invoices (B2G).
- An API for automated issuing, with full REST API documentation. Integration usually takes 2 to 3 days.
- We file the provider declaration with AADE for you, inside the 10-day window.
- A staging environment so you can test before going to production.
- Support in Greek and English, from a team working with the same myDATA error codes every day.
Start with a free account, or if issuing originates in your own system see what an API integration involves. If you would rather talk first, send us the document volume you expect per year.
Frequently asked questions
When does e-invoicing become mandatory for small businesses in Greece?
From 1 October 2026. Businesses with gross revenue above €1,000,000 in the 2023 financial year, as declared in their income tax return, have already been in scope since 2 March 2026 (Α.1128/2025, as in force).
Can I keep issuing invoices from my ERP after 1 October 2026?
No. AADE states explicitly that business management software (commercial, accounting or ERP) is not an accepted method of issuing invoices. Your ERP can remain the system you work in, but issuing and authentication go through a licensed YPAHES provider, usually by connecting the ERP to the provider API.
What is the transitional period to 31 December 2026 and who qualifies for it?
Between 1 October and 31 December 2026 you may meet the obligation gradually, using the other issuing methods in parallel. It applies only if a Declaration of Commencement of Electronic Issuance has been filed on time, with a start date no later than 1 October 2026. No declaration, no transitional period.
Who files the provider declaration with AADE?
The provider does, through the myAADE portal, within 10 days of the contract taking effect. The business is notified through myAADE e-notifications and by email, and has 10 days to accept or reject it. If that deadline passes with no action, the declaration is treated as accepted. If the provider fails to file on time, the obligation passes to the business, within 10 days of the provider deadline expiring.
What is the penalty for not issuing an electronic invoice in Greece?
It is treated as failure to issue an invoice. On VAT transactions the penalty is 50% of the VAT due, with a minimum of €250 for single-entry and €500 for double-entry books, doubling on repeat offences to 100% with minimums of €500 and €1,000. Moving goods without the required delivery documents carries €5,000 per tax audit for single-entry and €10,000 for double-entry books.
Are the article 71Θ tax incentives still available?
The deadline was 3 August 2026, two months before the mandate takes effect, and it required both filing the declaration and starting to issue exclusively through a provider within that window. The incentives were a 100% uplift on depreciation of equipment and software, and a 100% uplift on the cost of issuing, transmitting and archiving documents for the first 12 months. Chambers of commerce and industry bodies have asked for an extension, but nothing has been legislated. Check AADE or ask your accountant for the current position.
Is e-invoicing the same as myDATA reporting?
No. myDATA reporting means sending AADE the data from your documents. E-invoicing through a provider covers the whole cycle: issuing in a structured electronic format, authentication, delivery to the recipient, archiving and automatic transmission. One does not replace the other.
What changes on 12 October 2026 for delivery notes?
Phase B of digital stock movement monitoring becomes mandatory, covering loading, transhipment and receipt, with QR marking. The aggregate delivery note may still be issued on paper up to and including 11 October 2026.
Do I need an electronic invoice if my customer is abroad?
The obligation covers B2B transactions within Greek territory, plus sales of goods and supplies of services to businesses in third countries outside the EU. For transactions with businesses in other EU member states, e-invoicing remains optional for now.
Need help?
If you have a question about this topic or want to make sure everything is set up correctly, contact us and we will look at it together.