Client Access Licenses (CALs) are different from Windows Server software licenses. A Windows Server CAL is the license that gives users and devices the right to access a server installed with Microsoft Windows Server software.

Why should I buy CALs?

CALs are required by Microsoft licensing for all users or devices that access Windows Server Standard or Windows Server Datacenter. When a customer buys Windows Server Standard or Datacenter, they receive a server license that allows them to install the operating system on one computer. A server software license by itself doesn’t provide the license rights to allow anyone to connect to that computer, whether they work for the company or not. Instead, each user or device needs a CAL.

What are my CAL buying options?

User CALs
One user, unlimited devices
Ideal for companies with employees that use multiple devices.

Device CALs
One device, unlimited users
Ideal for companies with multiple users for one device, such as shift workers.

CALs are not included with any Windows Server 2012 or 2012 R2 editions.

No CALs required for Windows Server 2012 or 2012 R2 Essentials or Foundation.

CALs are required by Microsoft licensing for all users or devices that access Windows Server Standard or Windows Server Datacenter.

Windows Server 2012 CAL customer scenario

A small office with 15 users that access Windows Server 2012 R2 from multiple devices (desktops, laptops, tablets, phones) buys a server installed with Windows Server 2012 R2 Standard. They should also buy 15 Windows Server 2012 User CALs, one for each employee.

15 Users
15 User CALs
1 Server
1 Server License

Frequently Asked Questions

Are there Windows Server 2012 R2 CALs?
No. CALs were not re-versioned when 2012 R2 shipped. Windows Server 2012 CALs are the proper license for Windows Server 2012 R2 users or devices.
Are CALs included with Windows Server 2012 R2?
No. CALs are sold separately, which gives you flexibility to purchase only what you need now—and add more when you need them.
What is the difference between a server license and a CAL? Why do I need both?

The server license gives you the right to install and use the server software. A CAL grants a user or device the right to access the server software. This structure offers license affordability to organizations of all sizes.

When do I need to acquire a CAL?
You need a CAL as soon as users or devices access or use your server. Keep in mind that you don’t need CALs for unauthenticated access through the Internet.
Can I use a device CAL and a user CAL to access the same server?
Yes. Device, User, and RDS CALs are all designed to access the same server.
Is each CAL tied to a specific user or device?
Yes. CALs must be assigned to specific users or devices. If a user leaves the company or a device is retired, you can reassign the CAL.
I have some extra CALs from an older version that are not being used. Can I apply these to servers running a newer version?
No. CALs must be the same version as—or a more recent version of—the server software they are accessing.