The French institutional framework consists of a network of notaries, who have a monopoly on registering property transactions, and a national statistics body, Insee.
Notaries check the property rights, draw up the deed of sale, send the property documents to the mortgage registry and receive the property transfer rights in the name of the State.
By virtue of their function, notaries have access to the transaction price and to some of the housing characteristics that have to be mentioned in the deed of sale. In addition, every notary must send information on the sale price to the authorities, since the fees collected on the sale are dependent on the price. In theory, the data cover all sales, providing real transaction prices on a regular basis and over a long period of time. Information is available promptly as there is a time limit set for notaries to pass on all taxes, a limit that in recent years was reduced to one month.

The law of 28 March 2011 confirms the public service mission that notaries fulfil in this area. Data produced jointly by the Insee and the notaries are certified by the Authority of the Public Statistics.