The codice fiscale inverso is the process of extracting personal information from an existing Italian codice fiscale. While the standard use of the codice fiscale is to generate a unique alphanumeric code from a person’s data—such as name, surname, date of birth, gender, and place of birth—the inverse approach works backward. By analyzing the characters in the code, it is possible to determine key details about the individual, including their birth date and whether they were born in Italy or abroad. This makes the codice fiscale not just an identifier, but also a compact container of encoded personal data.

However, the codice fiscale inverso has practical and ethical limitations. Not all information can be perfectly reconstructed, since some parts of the code are designed to avoid duplicates rather than provide clarity, and homonyms can complicate interpretation. Additionally, privacy concerns are important: even though the codice fiscale follows a public algorithm, using inverse decoding must be done responsibly and typically only for legitimate administrative or educational purposes. As a result, the codice fiscale inverso is mainly used for verification, learning, or technical analysis rather than for official identification on its own.