The Codice Fiscale is supposed to be a unique value you get from the State (via the Agenzia delle Entrate), but the whole system is so outdated and badly design

The Codice Fiscale is supposed to be a unique value you get from the State (via the Agenzia delle Entrate), but the whole system is so outdated and badly designed that most websites just check that the inserted code corresponds to the data you inserted.