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licensing / Frequently Asked Questions
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Frequently Asked Questions

This article lists the answers to the most frequently asked questions (FAQs) about working with the Telerik UI for ASP.NET AJAX license key.

Does the license key expire?

Yes, the license key expires at the end of your subscription:

  • For trial users, this is at the end of your 30-day trial period.
  • For commercial license holders (as of 2025 Q2), this is when your subscription term expires.

You need to download and install a new license key after:

  • Starting a new trial
  • Buying a new license
  • Renewing an existing license
  • Upgrading an existing license

An expired perpetual license key is valid for all Telerik UI for ASP.NET AJAX versions published before the license expiration date.

Will Telerik UI for ASP.NET AJAX function with an expired license key?

This depends on the Telerik UI for ASP.NET AJAX license type (perpetual, subscription, or trial):

  • Perpetual licenses function normally with an expired license key, as long as the application is using a version that was released before the expiration date of the license.
  • Subscription licenses function normally in already deployed applications, but you cannot rebuild and republish the app.
  • Trial licenses function normally only within the 30-day trial period.

Scenarios that do not match the above three descriptions result in the following application behaviors:

I updated the Telerik UI for ASP.NET AJAX version in my project and license errors appeared. Why?

The most likely cause is that the new Telerik UI for ASP.NET AJAX version was released after the expiration date of your current license or license key. To fix this issue:

  1. Renew your Telerik UI for ASP.NET AJAX license if necessary.
  2. Download a new license key file and use it to activate the components.

Why do I keep seing errors about licenses.licx file after upgrading to Telerik UI for ASP.NET AJAX 2025 Q1?

Prior to 2025 Q1, Telerik Components were using the old Licensing Mechanism which has automatically generated a licenses.licx file containing information about the Telerik products.

To fix the issue, you can follow one of the two approaches below:

  • If you are using other .NET libraries that utilize the .NET Licensing Mechanism, open the licenses.licx file with a Text editor and remove the Telerik related records from it.
  • If nothing else uses the .NET Licensing Mechanism, you can safely delete the licenses.licx file from the project. If this file was commited to the source control, make sure you remove it from there as well.

Can I use the same license key in multiple builds?

You can use your personal license key in multiple pipelines, builds, and environments. However, each individual developer must use their own unique personal license key.

Do I need an Internet connection to activate the license?

No, the license validation and activation occur offline.

Do I have to add the license key to source control?

No, you do not have to add the telerik-license.txt license key file or its contents to source control.

Do not store the license key in plain text, for example, in a GitHub Actions Workflow definition. Build servers must use the TELERIK_LICENSE environment variable described in Adding the License Key to CI Services.

What happens if both the environment variable and the license key file are present?

If both the TELERIK_LICENSE environment variable and the telerik-license.txt file are present, then the environment variable will be used.

To use the license key file, unset the environment variable.

What happens if several license key files exist?

If both a global and a project-specific telerik-license.txt files exist, then the project-specific license key will be used.

My team has more than one license holder. Which key do we have to use?

Are earlier Telerik UI for ASP.NET AJAX versions affected?

No, versions up to 2024.4.1112 released prior to February 2025 do not require a license key.

See Also

In this article
Does the license key expire?Will Telerik UI for ASP.NET AJAX function with an expired license key?I updated the Telerik UI for ASP.NET AJAX version in my project and license errors appeared. Why?Why do I keep seing errors about licenses.licx file after upgrading to Telerik UI for ASP.NET AJAX 2025 Q1?Can I use the same license key in multiple builds?Do I need an Internet connection to activate the license?Do I have to add the license key to source control?What happens if both the environment variable and the license key file are present?What happens if several license key files exist?My team has more than one license holder. Which key do we have to use?Are earlier Telerik UI for ASP.NET AJAX versions affected?See Also
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