Buy Windows Server CALs – Client Access Licenses for legally compliant server access

Anyone running a Windows Server needs not only the server license but also a corresponding Client Access License (CAL) for every user or device that accesses the server. Without valid CALs, access to Windows Server services is unlicensed, which can result in significant back payments during license audits. At Lizenzindustrie, you can obtain all current Windows Server CALs as verified licenses—delivered immediately via email, at a price up to 70% below the official list price.

What is a Windows Server CAL?

A Windows Server Client Access License (CAL) is the access license that authorizes each user or device to access the services of a Windows Server. It complements the server license and is mandatory under Microsoft’s licensing model for Windows Server.

Specifically, this means: If 20 employees in your company access a Windows Server—whether for file sharing, Active Directory authentication, printing services, or other server functions—you’ll need 20 Windows Server CALs in addition to the Windows Server license. Without these CALs, these employees’ access is unlicensed, even if the server software functions properly.

Important to know: A Windows Server CAL is not limited to a specific server version. A newer CAL version also grants access to older server versions—so a Windows Server 2022 CAL also allows access to Windows Server 2019, 2016, or earlier. Conversely, an older CAL cannot be used to access a newer server version.

User CAL or Device CAL – What’s the Difference?

Windows Server CALs come in two variants that differ in how they are assigned:

User CAL – The User CAL is tied to a specific person. A user with a User CAL may access the Windows Server from any number of devices—from a desktop PC in the office to a laptop in a home office to a smartphone while on the go. User CALs are the better choice when employees access the server from multiple devices or when employees work from home or while traveling.

Device CAL – The Device CAL is tied to a specific device. A device with a Device CAL can be used by any number of users to access the Windows Server. Device CALs are the better choice when multiple users share the same device—for example, at shift-based workstations, shared terminals, or in production environments where a single PC is used by multiple employees across different shifts.

A practical rule of thumb is: If there are more devices than employees → User CALs. If there are more employees than devices → Device CALs. If you’re unsure, we’re happy to help—just get in touch.

All Windows Server CAL versions at a glance

• Windows Server 2025 CAL
• The latest CAL version—grants access to Windows Server 2025 and all earlier versions. The top choice for companies running Windows Server 2025 or planning for the long term.
• Windows Server 2022 CAL
• The most popular CAL version—grants access to Windows Server 2022 and all earlier versions. Offers a balanced price-performance ratio for companies using Windows Server 2022.
• Windows Server 2019 CAL
• Grants access to Windows Server 2019 and all earlier versions. The most affordable option for companies with Windows Server 2019 infrastructures.
• Windows Server 2016 CAL
• Grants access to Windows Server 2016 and earlier versions. For existing Windows Server 2016 environments.
• Windows Server 2012 CAL
• For existing Windows Server 2012 and 2012 R2 infrastructures. Recommended exclusively for legacy environments.
• Windows Server 2008 CAL
• For the oldest legacy infrastructures running Windows Server 2008 and 2008 R2. Suitable only for isolated, specialized environments.

How many CALs do I need?

The number of CALs required depends on the CAL type selected.

For User CALs, the required number corresponds to the number of people accessing the Windows Server—regardless of how many devices they use to access it. 20 employees, all of whom access the server → 20 User CALs.

For Device CALs, the required number corresponds to the number of devices used to access the Windows Server—regardless of how many people use each device. 15 PCs, all of which access the server → 15 Device CALs.

Important: CALs do not need to be purchased for external internet access to public web servers. Only internal users and devices that access Windows Server services require CALs.

How to Purchase from Lizenzindustrie

Purchasing Windows Server CALs from Lizenzindustrie is incredibly easy. Select the desired version and CAL type, specify the quantity, add to cart, and complete the purchase—you’ll receive your license keys immediately via email. No waiting, no physical shipping.

• ✔ Instant delivery of license keys via email
• ✔ Verified licenses—100% activatable via Microsoft servers
• ✔ Up to 70% cheaper than the official Microsoft list price
• ✔ User & Device CAL – both variants available
• ✔ All versions – available from 2008 through 2025
• ✔ Legally compliant – verified licenses from EU retailers
• ✔ Fast support – we’ll help you immediately with any licensing questions

Not sure which CAL version or type is right for your infrastructure? Contact us—we’ll advise you free of charge and help you find the most cost-effective solution.

Frequently Asked Questions About Windows Server CALs

Does the CAL version have to match the server version?

Not necessarily. Newer CAL versions also grant access to older server versions. A Windows Server 2022 CAL therefore allows access to Windows Server 2022, 2019, 2016, and older versions. However, older CALs may not be used for newer server versions—a Windows Server 2019 CAL does not grant access to Windows Server 2022.

Do I need CALs for external internet access to my web server?

No. No Windows Server CALs are required for anonymous external internet access to public web servers. CALs are only required for internal users and devices that access Windows Server services.

What is the difference between a User CAL and a Device CAL?

A User CAL is tied to a specific person and allows that person to access the server from any number of devices. A Device CAL is tied to a device and allows any number of people to access the server via that device. User CALs are suitable for mobile and home office workstations, while Device CALs are suitable for shared workstations and shift systems.

Does a Windows Server CAL also apply to Exchange Server and Remote Desktop Services?

No. Windows Server CALs only grant access to basic Windows Server services. To access Exchange Server, additional Exchange Server CALs are required. For Remote Desktop Services, additional RDS CALs are required.

How quickly will I receive my license keys?

Immediately after purchase—your activation keys will be automatically sent via email. Activation takes place directly through the official Microsoft activation servers.