NISS Validator

Portuguese social security number (NISS) — 11 digits with embedded check digits.

Portugal Validation Generation

Try the demo NuGet: DocumentNumber.Portugal.Niss.Validator

How validation works

The validator checks the 11-digit NISS structure and recomputes the check digits used by Segurança Social before accepting the number.

Install the package

bash

dotnet add package DocumentNumber.Portugal.Niss.Validator

Validator in C#

Program.cs

using DocumentNumber.Portugal.Niss.Validator;

var validator = new NissValidator();
var isValid = validator.Validate("14165152022");

Console.WriteLine(isValid ? "Valid" : "Invalid");

Live example

14165152022 — a real NISS value accepted by the validator

Try NISS validation

Runs the exact same library code your application uses. Nothing you enter is stored.

Frequently asked questions

What is NISS?

Portuguese social security number (NISS) — 11 digits with embedded check digits.

How does NISS validation work?

The validator checks the 11-digit NISS structure and recomputes the check digits used by Segurança Social before accepting the number.

How do I install the NISS validator package?

dotnet add package DocumentNumber.Portugal.Niss.Validator

Is the value I enter in the demo stored?

No. Demo inputs are processed in memory for the current request only and are never persisted or shared.