Italy Postal Code (CAP) Format Explained

The Italian CAP is a five-digit numeric code. It has no letters, no spaces within the number and no separator. It is written before the town on the last line of the address.

What the CAP represents

The code is designed for mail sorting by the postal operator. The first digits indicate a broad part of the country, and the following digits narrow the code to a provincial area and then to a town or zone. The code does not follow the administrative boundaries of provinces or municipalities exactly, so two neighbouring towns in different provinces may have similar codes, and a code should not be used to infer an administrative area with certainty.

Towns and cities

A small comune normally has one CAP that covers the whole municipality. A larger city is divided into zones, and each zone has its own CAP. Rome and Milan are well-known examples, where the code varies by district and sometimes by street. In cities of this kind, the CAP is therefore a property of the street and number, not of the city name alone. Some cities also have a general code used for mail addressed to post office boxes.

Examples of valid format

These generic examples illustrate the shape only:

• 12345
• 00123
• 98765

Leading zeros are normal. Software should keep the CAP as a five-character text value.

Common mistakes

• Storing the CAP as a number and losing the leading zero.
• Using the code of the city centre for every address in a large city.
• Putting the CAP after the town name, which follows the English habit and not the Italian one.
• Adding the letter I as a country prefix on domestic mail.
• Confusing the CAP with the telephone area code or a province abbreviation.

Validation tips

A basic check is five digits. Whether a code actually belongs to a given street requires a lookup in the postal operator's directory, as explained in how to find an Italian CAP.

How UPCS relates

A UPCS code such as IT-XXXX-XXXX (placeholder) is not a CAP. It refers to a 3 m x 3 m cell and can be saved beside the CAP when the exact point matters. Return to the Italy overview or see how Italian addresses are written.