How the Codice Fiscale Control Character Works

The 16th and final character of the Italian codice fiscale is not random: it is a checksum computed from the other 15 characters, and it is the fastest way to catch a typo.

The method

• Characters in odd positions (1st, 3rd, 5th...) are converted with one table of values; characters in even positions with another.
• All values are summed, divided by 26, and the remainder maps to a letter (0=A, 1=B, ... 25=Z).
• A single wrong character in the first 15 almost always produces a wrong control character — that is exactly the point.

Why it matters

Before trusting a hand-calculated code, always verify the control character. A mismatch means something in the data is wrong — usually the name spelling, the birthplace Belfiore code, or the +40 rule for women.

Verify yours

Run a formal verification of your codice fiscale — the check runs in your browser and nothing is stored. For the full method, see the complete calculation guide.