---
title: "License activation | Nutrient .NET SDK"
canonical_url: "https://www.nutrient.io/guides/dotnet/csharp/license-activation/"
md_url: "https://www.nutrient.io/guides/dotnet/csharp/license-activation.md"
last_updated: "2026-10-08T00:00:00.000Z"
description: "Activate your Nutrient .NET SDK license before running SDK operations."
---

# License activation

PDF and Office document processing features in Nutrient SDK run under your license key. Activating the license removes trial limits and watermarks and unlocks the capabilities your plan includes. Register the key once, before any other SDK call.

## Activate your license with the.NET SDK

Register your license key at application startup. Without a key, the SDK runs in trial mode — full functionality, limited to one hour per process.

## Register the license key

Import the Nutrient namespace and register the key before opening any document:

```csharp

using Nutrient;

try
{
    // Replace the empty string with your license key:
    // License.RegisterKey("YOUR_LICENSE_KEY_GOES_HERE");
    License.RegisterKey("");

```

## Use the SDK

With the license registered, every SDK feature is available. This example converts a document to PDF:

```csharp

    using Document document = Document.Open("input.pdf");
    document.ExportAsPdf("output.pdf");
    Console.WriteLine("Successfully converted to output.pdf");
}
catch (NutrientException e)
{
    Console.Error.WriteLine($"Error: {e.Message}");
    Environment.Exit(1);
}

```

## Handle errors

An invalid or expired key surfaces as a `NutrientException` on the first SDK call that requires it. Catch it as shown above to log the failure and exit cleanly.

## Trace evaluated features in trial mode

Use `License.TraceFeatures()` in trial mode to list the licensed SDK components your application evaluated during the current session. This helps you identify which components a production license needs to cover.

In version 14.4.9, `License.TraceFeatures()` reports every licensed component used in trial mode. Earlier builds could return an empty list or only a single entry.

## Conclusion

Your application is licensed and ready to use every SDK capability your plan includes. Get your license key at [my.nutrient.io](https://my.nutrient.io/users/sign_in).
---

## Related pages

- [Nutrient.SDK package](/guides/dotnet/csharp.md)
- [Changelog for Nutrient.SDK](/guides/dotnet/csharp/changelog.md)
- [.NET SDK sample downloads](/guides/dotnet/csharp/downloads.md)