Abstract: The present application relates to a method for synchronizing heterogeneous databases using at least one processor, a first user database, a second user registers database, a third location criteria database and a fourth location occupancy database, the inputs of said first user database being likely to match the inputs of the third location criteria database, with the method including: a step of modification wherein the inputs of the fourth location occupancy database and the inputs of the second user register database are modified in response to a request; prior to the modification, the processor processes the request so as to check the matching between the inputs of the third location criteria database and the inputs of the first user database; depending on the checking, the processor sends a positive acknowledgement to the first location occupancy database and to the second user register database so as to carry out the modification.