Goodbye to real estate tax evasion: the Revenue Agency is delivering about 20,000 letters of compliance to owners of properties that were never declared to the Land Registry. To catch those who do not comply, tax authorities used artificial intelligence to cross-reference cadastral map data with aerial photographs (orthographs) provided by the Agency for Agricultural Payments. The operation, which commenced in early 2025, aims to identify the so-called "ghost houses". However, the tax authorities are also focusing on minor irregularities that have evaded public record-keeping, such as raised floors, attics that have been converted into habitable spaces, new garages, changes in intended use, and volumetric modifications. The analyses have now covered 96% of the country and will be completed by the end of this year. The initial 20,000 reports will focus on high-profile cases of properties that are absolutely unknown to tax officials. Further investigations—which began with 21,600 letters in the second quarter of 2026—will focus on infractions involving properties renovated with building incentives.