French tax authority extends AI detection of undeclared pools nationwide

France's public finance directorate, the DGFiP, extended its "Foncier innovant" tool to the whole country in 2022, after testing it in nine departments (France's county-level administrative areas). The system uses artificial intelligence to analyse aerial photographs and spot swimming pools that owners had not declared to the tax authorities.

The tool compares what the images show with the property records held by the administration. Where a pool appears in the pictures but not in the records, the case is flagged for review. Tax officials then check the file and can update the property's rental value, which is the basis for local property taxes, so the owner owes more.

The project was developed with private technology partners and drew on aerial imagery already published by the national mapping agency. It mattered because it was one of the first large-scale uses of AI by French tax services to find hidden taxable property. It raised debate over privacy and over how far automated image analysis should be used to monitor private homes. The same approach later served as the basis for detecting other kinds of undeclared structures.