Using AI technology developed by Google and Capgemini, French tax authorities have spotted 20,000 undeclared pools in private properties, landing owners with bills amounting to approximately €10 million.
In France, property modifications including swimming pools have to be declared to the tax office within 90 days of completion because property taxes are based on the value of the property.
According to La Parisien, a 30 square meters pool could result in an extra €200 property tax annually.
The AI technology can spot pools from aerial images. The project was launched in 2021 as a test in several French departments and spotted 20,356 pools. The tax office said on Monday that the system will be used across the country.
However, the technology is not perfect. In April, it was reported that the Google-Capgemini software had a margin of error of 30%. The system made mistakes like mistaking solar panels for pools and it cannot pick up pools that are hidden by shadows of buildings and under trees.
The tax office said it wants to use the technology to spot other taxable modifications like verandas and annexes.
“We are particularly targeting house extensions like verandas, but we have to be sure that the software can find buildings with a large footprint and not the dog kennel or the children's playhouse,” Antoine Magnant, the deputy director general of public finances, told Le Parisien newspaper.
It is not clear how that would work because, from the aerial images, the system cannot tell if a rectangular shape is actually an extension or just a tenet or something placed on the ground.