As of today, 1 December, IRIS payments are mandatory for all retail businesses — from small shops to major chains — which must now integrate their POS devices, cash registers, and AADE systems into a unified environment.

For consumers, this means easier and more immediate transactions. For professionals, however, a new reality begins, marked by strict rules, continuous cross-checking, and a significant cost of compliance.

AADE has completed the new operating framework for Instant Payments and now sets a clear rule: every payment, whether by card or IRIS, must pass through the cash-register system and be issued a receipt in real time.

The Ministry of Finance and AADE assure that there will be a transitional period of guidance rather than immediate fines, especially when technical issues arise that are not the business’s fault. Still, the market worries that if POS–cash register–Taxisnet connections do not function flawlessly, inaccurate readings and unfair penalties may occur.

However, the new framework includes high penalties for those who do not adapt. A €10,000 fine applies to businesses using single-entry bookkeeping, and €20,000 for those using double-entry bookkeeping, if they do not accept IRIS or have not completed the integration properly. In settlements with up to 500 residents and islands with fewer than 3,100 residents, fines are reduced by half. Meanwhile, companies managing POS systems face fines ranging from €100,000 to €300,000, and even failure to upgrade a single terminal results in a €500 penalty per device.

From mid-2026, IRIS will expand to Italy, Spain, Portugal, Scandinavia, and Poland through EuroPA, enabling instant money transfers beyond Greece.