myDATA & E-Invoicing Compliance
myDATA setup, correct invoice classification, mismatch reconciliation and a smooth move to mandatory B2B e-invoicing in Greece.
Through myDATA, AADE sees every business's income and expenses almost in real time and cross-checks them against what customers and suppliers report. One wrong classification or an invoice that was never transmitted can lead to queries, fines or a distorted picture in your tax returns.
Our Thessaloniki accounting team handles myDATA from the initial setup to the monthly check. In 2026 we are preparing our clients for the next phase of mandatory e-invoicing and for the digital dispatch note, so the change does not interrupt invoicing or the movement of goods.
Who it’s for: Every business that issues or receives invoices in Greece: freelancers, sole traders, IKE, EPE and AE companies, and subsidiaries of foreign groups, especially those now entering mandatory e-invoicing.
Our myDATA and e-invoicing services
myDATA Setup
Registration, API credentials and connecting your accounting or invoicing software to AADE's myDATA platform.
Invoice Classification
Correct classification of income and expenses with AADE codes, and automation rules that cut manual work.
B2B E-Invoicing
Choosing a provider or AADE's timologio app, setting up the workflow and testing before your mandatory start.
Mismatch Resolution
Finding and fixing differences between what you report and what your counterparties report, and reconciling myDATA with your books.
Digital Dispatch Note
Organizing digital goods movements: issuing before dispatch, the QR code, confirmation of receipt and quantity receipt notes in Phase B.
Compliance Monitoring
Ongoing tracking of AADE decisions and deadlines, with timely changes to your setup.
How we get your myDATA in order
Readiness check
We review your invoices, the software you use and current mismatches in myDATA.
Map of obligations
We tell you which e-invoicing phase applies to you, whether the digital dispatch note affects you and what needs to change.
Setup and testing
Together with your vendor we configure series, classifications and workflows and check test documents.
Monthly check
Every month we reconcile myDATA with your books and correct mismatches before they become a problem.
E-invoicing and dispatch note dates for 2026-2027
The dates as they currently stand under AADE decisions. If they change, we tell our clients right away.
- Businesses with 2023 gross revenue above €1,000,000: mandatory B2B e-invoicing from 2 March 2026.
- All other businesses in scope: from 1 October 2026, with a transition period to 31 December 2026 (decision A.1128/2025).
- Digital dispatch note, Phase B: mandatory from 12 October 2026, with TARIC coding from 1 January 2027.
- Transmission of all invoices and classifications to myDATA within the deadlines AADE sets for each category.
Why leave myDATA to us
Accounting and technical know-how
We know what AADE asks for and how it must end up in the books, so we fix issues at the root.
Updates for your case
We follow every decision and extension and tell you what changes for you, not in general.
Fewer fines and queries
Monthly reconciliations catch mismatches before AADE does.
Support for foreign companies
We explain myDATA and e-invoicing in English and German to subsidiaries and branches of foreign groups.
myDATA and e-invoicing: frequently asked questions
When does e-invoicing become mandatory for my business?
It depends on your 2023 gross revenue. Businesses above €1,000,000 joined on 2 March 2026 and the remaining businesses in scope from 1 October 2026, with a transition period to the end of the year. We confirm which group you belong to.
Do I need a provider or is AADE's timologio app enough?
Both routes are legal. Timologio is free and suits a small number of invoices, while a provider connects to your ERP and works better for businesses with many documents.
What happens if there are mismatches in myDATA?
AADE cross-checks your data with what customers and suppliers report. Mismatches can lead to queries or an audit, which is why we check them every month and correct them properly.
Does the digital dispatch note apply to me?
It does if you move goods with dispatch notes. Phase B becomes mandatory on 12 October 2026 and gives the recipient an active role in confirming receipt. We check whether and how it applies to your business.
Interested in myDATA & E-Invoicing Compliance?
Tell us what you need. We reply within one business day.