Regex for Italian CAP postal
5-digit Italian Codice di Avviamento Postale.
The Italian CAP postal regex is ^\d{5}$ — copy it below, or open it in the explainer for a token-by-token breakdown.
The pattern
What it matches
001002010080100
What it doesn't match
001100001ROMA1
Notes & gotchas
Italian postal: 00100 (Rome), 20100 (Milan), 80100 (Naples), 50100 (Florence). 5 digits, never starts with letters.
Code in your language
Use the explainer's Code tab to generate ready-to-paste snippets in JavaScript, Python, Java, .NET, Go, Ruby, and PHP for this pattern.
Open in explainer →Token-by-token breakdown
Every part of the pattern, left to right:
| Token | Meaning |
|---|---|
^ | start of string (or line in multiline mode) |
\d{5} | exactly 5 times: digit (0–9) |
$ | end of string (or line in multiline mode) |
About this pattern
European Union identifiers follow standards set by individual member states with EU-wide coordination (VAT VIES, IBAN/SEPA, etc.). The regex validates structure; for production use, validate via the appropriate registry.
Quick usage in different languages
This exact pattern — with the correct escaping and idioms for each language:
- JavaScript:
/^\d{5}$/.test(value) - Python:
re.match(r"^\d{5}$", value) - Java:
Pattern.compile("^\\d{5}$").matcher(value).matches() - C# / .NET:
Regex.IsMatch(value, @"^\d{5}$") - Go:
regexp.MustCompile(`^\d{5}$`).MatchString(value) - Ruby:
/^\d{5}$/.match?(value) - PHP:
preg_match('~^\d{5}$~', $value)
The explainer’s Code tab regenerates these for any pattern you paste, and the downloadable cheat sheet bundles the breakdown, all seven snippets, and the pitfalls below onto one printable page.
Common pitfalls
- Anchored to the whole string. This pattern uses ^ and $, so it requires the entire input to match. To find it inside a longer text, drop the anchors and use the global (g) flag.
- Escape it correctly per language. In Java and JavaScript strings each backslash must be doubled (\\d); in Python, Go, and C# use raw/verbatim strings so the backslashes survive.
- Validate beyond format. Matching the format doesn't guarantee the value is real. Confirm the italian cap postal against a source of truth (database, API, or checksum) where it matters.
Related patterns
More patterns in the Europe 🇪🇺 category:
- French phone (+33)
- Spanish postal code
- German phone (+49)
- Polish postal code
- Spanish NIE
- Dutch postal code
See also
Browse all 300 patterns in the library, or open this regex in the interactive explainer to see a token-by-token breakdown, test against custom input, and generate code in seven languages.