Greece is in the process of implementing the most significant reform of its property record-keeping in decades. A unified digital register — the platform known as MIDA, operating under the Independent Authority for Public Revenue — will consolidate into a single system the data that has historically been held across multiple separate institutions: the Hellenic Cadastral, the tax authority's E9 property declarations, ENFIA assessments, rental registrations, utility records, and building permit data. Cross-referencing between these sources, which previously required significant manual effort, will become automatic.

The practical implication for foreign owners is straightforward: data that has been inconsistent, incomplete, or simply never corrected will become visible in a way it has not been before. The window for addressing these issues while corrections are straightforward is now.

What the Register Brings Together

Each property will eventually hold a single digital identity containing its legal status as recorded in the Cadastral, its declared characteristics in the E9 (surface area, floor level, ownership share, usage, occupancy status), its ENFIA assessment, its permit status as recorded with the Technical Chamber of Greece, its utility connection data, and any registered rental arrangements — including whether the property is declared vacant, owner-occupied, long-term let, or operating as a short-term rental.

The two identifiers that link these records are the ATAK number, which is the tax authority's property reference, and the KAEK code, which is the Cadastral 's spatial identifier. A significant number of properties — particularly older ones, those acquired through inheritance, and those that have changed hands informally or under previous administrative frameworks — carry discrepancies between these two identifiers. These discrepancies are now the subject of active cross-checking.

From January 2026, the tax authority has begun extensive cross-referencing between property declarations and Cadastral records. Property owners will receive notifications prompting them to review, confirm, or correct their recorded information. The full Unified Property Registry, developed by the Hellenic Cadastral and expected to be operational by June 2026, will extend this consolidation further — integrating legal, planning, forestry, tax, energy, and administrative data into a single accessible profile.

Why This Matters for Foreign Owners Specifically

Foreign nationals who own property in Greece — whether acquired through purchase, through the Golden Visa program, or through inheritance — carry the same obligations as domestic owners in relation to property registration and tax declaration. The distance from which they manage these matters does not diminish those obligations, and the new system is not designed with any distinction between resident and non-resident owners.

Several categories of discrepancy are particularly common among older foreign-held properties:

E9 declarations that do not reflect the property as it actually exists. Surface area, floor level, and occupancy status are all declared on the E9. Properties that have been extended without permit, subdivided, or left vacant without formal declaration may carry E9 entries that no longer match the physical reality or the Cadastral record.

ATAK and KAEK identifiers that do not correspond. Properties acquired before the Cadastral system reached a given area, or transferred through informal or inheritance procedures, may hold tax records and spatial records under different references. The new system will flag these mismatches.

Undeclared rental income. The register will cross-reference declared occupancy status against utility consumption data and rental platform activity. Properties appearing on short-term rental platforms while declared as vacant on tax returns represent an obvious target for automated cross-checking.

Unresolved inheritance registrations. In Greece, inherited property must be formally accepted and registered within defined deadlines. A significant proportion of foreign-held property — particularly among diaspora owners — was acquired through inheritance without all the required steps having been completed. These properties may appear in the Cadastral under deceased owners or in forms that do not reflect current ownership.

What to Do Now

The practical steps for foreign owners are not complicated, but they require access to Greek administrative systems and, in most cases, professional assistance in Greece.

Review the E9 declaration. Log into myAADE or appoint a local accountant or tax representative to do so. Verify that the surface area, floor level, occupancy status, and usage type accurately reflect the property. Any discrepancy should be corrected before the automated cross-checks identify it rather than after.

Verify the Cadastral entry. Confirm that the KAEK code, the recorded boundaries, and the ownership details match what appears in the title deed. Where the Cadastral is still in a transitional phase in a given municipality, check the status with the relevant land registry.

Ensure ENFIA is current. Unpaid ENFIA is a charge that sits against the property and must be cleared before any transfer. Foreign owners who have not been receiving assessments — because the tax authority does not hold a current correspondence address — should establish whether arrears have accumulated.

Regularize any outstanding planning violations. Unauthorized constructions or undeclared square footage must be addressed. The new register will make the gap between the permitted building and the declared building measurable in ways it has not previously been.

The reform is intended to benefit compliant property owners as much as to identify non-compliance. A property with consistent, accurate records across all systems will transact more cleanly, access subsidy programs more directly, and carry less risk for any future buyer. For foreign owners whose Greek property holdings have been managed at arm's length, now is the right moment to bring those records into order.

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