Greek Tax Returns 2026: E3 Form, New Activity Codes (KAD) and myDATA
This year the Greek E3 business income statement is built on myDATA data and the new EU-aligned activity codes. Here is what to check before you file: pre-filled income, KAD corrections, TaxisNet credentials and penalty-free amendments.
Filing Greek tax returns for 2026 brings significant changes for freelancers and businesses. The full rollout of myDATA, the e-invoicing platform of AADE (the Greek tax authority), the growing role of the licensed e-invoicing provider (YPAHES) in everyday transactions, and the recent migration of Greek business activity codes (KAD) to the European standard make this year's E3 form, the business income statement, more complex than ever.
This guide walks you through the points that deserve the most attention before you finalise your return.
1. New Activity Codes (KAD) and the E3 Form: The First Big Cross-Check
The transition to the new European coding system directly affects your return.
- Automatic update: Your main business activity code (KAD) is pulled automatically from the AADE registry into the E3 form.
- Accuracy check: Before you finalise the return, make sure the KAD shown matches your actual business activity. If the automatic mapping carried out in March contains errors, you can correct them without a penalty until 1 June 2026.
2. myDATA and Pre-Filled Income and Expenses
The myDATA platform is now the foundation for completing the E3 form. The data transmitted by you or by the licensed e-invoicing provider you use is pre-filled into the corresponding fields.
- Watch out for discrepancies: The pre-filled figures are indicative. If the amounts in myDATA differ from your accounting books, you are obliged to make corrections.
- The provider's role: Businesses that issue invoices through a licensed e-invoicing provider ensure their revenue is transmitted to myDATA instantly and correctly, reducing the risk of errors when the tax is assessed.
3. Spouses and Personal TaxisNet Credentials
For married couples or civil partners filing a joint E1 return (the annual personal income tax return):
- If the spouse is self-employed, she must file her E3 form using her own personal TaxisNet credentials.
- Using the main filer's credentials for the spouse's E3 is not possible, which guarantees the return carries the correct digital signature.
4. Agricultural Income and OPEKEPE Subsidies
For farmers, separating the different types of aid is key to calculating the tax correctly:
- Basic payment: Taxed from the first euro in Table C of the E3 form.
- ELGA compensation payments: These do not count as income and are not taxed, but they must be declared correctly so they are not counted towards the VAT exemption thresholds.
5. Amended Returns Without Penalties
If you spot an omission after filing:
- You can file an amended E3 return, and it counts as filed on time, provided the original was submitted within the deadline and the correction is made before the filing period closes.
- The new return fully replaces the previous one and the tax outcome on the E1 is recalculated.
Conclusion
This year's E3 demands close monitoring of your myDATA data and verification of the new KAD codes. Modern tools, such as a licensed e-invoicing provider, make the process easier, but the final check before submitting to AADE remains the responsibility of the taxpayer and their accountant.
Frequently asked questions
What is the E3 form in Greece?
The E3 is the business income statement that freelancers and companies in Greece file alongside the E1 personal income tax return. In 2026 it is largely pre-filled from myDATA, the e-invoicing platform of AADE, the Greek tax authority.
Until when can I correct a wrong KAD activity code without a penalty?
If the automatic mapping of your business activity codes (KAD) to the new European standard contains errors, you can correct them penalty-free until 1 June 2026. Check that the KAD shown on your E3 matches your actual activity before finalising.
What if the pre-filled myDATA figures differ from my books?
The pre-filled amounts are indicative, not binding. If the myDATA figures differ from your accounting records, you are obliged to correct them before submitting the return.
How does an e-invoicing provider make Greek tax filing easier?
When you issue invoices through an AADE-certified e-invoicing provider such as Wrapp, your revenue is transmitted to myDATA instantly and correctly. That keeps the pre-filled E3 figures accurate and reduces the risk of discrepancies when your tax is assessed.
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.