Codice Fiscale

A lightweight, dependency-free .NET library for Italian fiscal code (codice fiscale), VAT number (partita IVA) and IBAN validation.

All validation logic runs locally. No HTTP calls, no external services, no data ever leaves your application.

Installation

 dotnet add package CodiceFiscale

Features

• Fiscal code validation (format + checksum)
• Fiscal code generation from personal data
• Cross-check: does this fiscal code match these personal details?
• Italian VAT number validation (standard, public entity, foreign)
• IBAN validation (mod97, all countries)
• Comuni and codici Belfiore embedded dataset (no external files needed)
• Zero dependencies
• Fully tested

Usage

1. Validate a fiscal code

   using CodiceFiscale;
   
   bool isValid = CodiceFiscaleValidator.IsValid("RSSMRA80A01H501U"); // true
   
   Generate a fiscal code
   
   var data = new PersonalData
   {
       FirstName       = "Mario",
       LastName        = "Rossi",
       Gender          = Gender.Male,
       DateOfBirth     = new DateOnly(1980, 1, 1),
       CityOfBirth     = "Roma"
   };
   
   string cf = CodiceFiscaleGenerator.Generate(data); // "RSSMRA80A01H501U"

2. Cross-check fiscal code against personal data

   bool matches = CodiceFiscaleMatcher.Matches(
       fiscalCode: "RSSMRA80A01H501U",
       firstName:  "Mario",
       lastName:   "Rossi",
       gender:     Gender.Male,
       dateOfBirth: new DateOnly(1980, 1, 1),
       cityOfBirth: "Roma"
   ); // true

3. Parse a fiscal code

   CodiceFiscaleData parsed = CodiceFiscaleParser.Parse("RSSMRA80A01H501U");
   
   parsed.Gender       // Male
   parsed.DateOfBirth  // 1980-01-01
   parsed.BelfioreCode // "H501"
   parsed.CityOfBirth  // "Roma"

4. Validate an Italian VAT number

   bool isValid = ItalianVatCodeValidator.IsValid("12345670017"); // true

5. Validate an IBAN

   bool isValid = IBANValidator.IsValid("IT60X0542811101000000123456"); // true

Edge cases handled

• Names with fewer than 3 consonants (Re, Li, Yu)
• Names with apostrophes and accents (D'Amico, Rosà)
• Foreign-born individuals (Belfiore code Z + country number)
• Omocodia (alternate fiscal codes with letters replacing digits)
• VAT numbers for public entities (starting with 8 or 9)
• Obsolete municipalities (comuni soppressi)

Why not an API?

Fiscal codes and VAT numbers are personal data. Sending them to a third-party server to validate them raises immediate GDPR concerns. This library validates everything locally. The data never leaves your application.

Dataset

The comuni/Belfiore dataset is sourced from ISTAT open data and embedded directly in the library binary. No external files are required at runtime.

The dataset is updated with each minor release to reflect municipality changes (merges, renames, new comuni).

Contributing

Contributions are welcome. If you find a fiscal code that validates incorrectly, please open an issue with:

1. The fiscal code (you can anonymise it — just keep the structure)
2. The personal data it should/should not match
3. The expected result

License

Municipalities data

https://comuni-ita.readme.io/reference/getcomuni

Build

dotnet build
dotnet test

Launch DocFX locally

docfx .\docfx.json --serve