myDATA — Greece’s real-time transaction reporting
What it is
myDATA (the AADE “e-books” / e-ledgers platform) receives invoice and accounting data from businesses in near real-time and validates each document with a unique MARK identifier and a QR code. That validated data then feeds pre-filled VAT returns, so the figures you report and the figures AADE holds are reconciled at source.
Who it applies to
effectively all businesses that keep books, sole traders included. If you issue invoices or keep accounts in Greece, you’re in myDATA.
Format and timing
documents follow the European standard EN 16931 (XML). Data is submitted monthly or quarterly, by the 20th day after the period, depending on the size of the business. QR codes have been mandatory on documents issued by ERP/business software since 1 January 2024.
Free tools
businesses without commercial or ERP software can use AADE’s free timologio app and myDATAapp to issue and transmit documents — so myDATA compliance doesn’t require buying software, though many businesses use certified providers for convenience.
Penalties
myDATA non-compliance carries fines of €250–€10,000, depending on the size of the business and the duration of the breach.
How it connects to everything else
myDATA is the backbone the other regimes report into. The POS / cash-register interconnection feeds retail card data to it, and B2B e-invoicing layers structured invoices on top. AADE runs cross-checks across all of these plus IRIS — so the data you send to myDATA is compared against your other reported flows.
Foreigner lens
the obligation is the same regardless of nationality; access is through your business TaxisNet credentials. A non-EU business may operate through a fiscal representative who handles filing.
How to stay compliant
make sure your invoicing tool (whether the free AADE app or certified software) actually transmits to myDATA with the MARK and QR, and that you submit by the 20th for your period. The free tools cover small businesses; if you use an ERP, confirm it’s certified and QR-enabled. Confirm your exact cadence (monthly vs quarterly) for your taxpayer category with AADE.
Related
fiscalization overview · B2B e-invoicing · POS & cash-register interconnection · business tax & VAT
This is general information, not tax or compliance advice. myDATA rules and cadences change — confirm at aade.gr / mydata.aade.gr and with your accountant. WTP Finance is informational only.