Windows Server CALs Explained: User CAL vs Device CAL in Plain English
Windows Server

Windows Server CALs Explained: User CAL vs Device CAL in Plain English

3 min read

Buying the server license is only half of Windows Server licensing. The other half is Client Access Licenses, or CALs. Skipping them does not stop the server from working, but it leaves you out of compliance, and a licensing review will treat missing CALs exactly like a missing server license.

What a CAL actually is

A CAL is not software. It is a purchased right for one user or one device to access the services of a Windows Server (file shares, Active Directory sign-in, printing, intranet applications). Windows Server 2022 Standard and Datacenter both require CALs; the server edition does not change that.

There are two types, and you choose per person or per machine, not per server:

  • User CAL: licenses one named person to connect from any number of devices (laptop, phone, home PC).
  • Device CAL: licenses one physical device that any number of people may use.

How to choose in practice

The rule of thumb is simple: compare people to devices and license the smaller number.

  • An office where every employee has a laptop plus a phone: User CALs win, because each person would otherwise need two Device CALs.
  • A warehouse with 3 shifts sharing 10 scanning stations: Device CALs win, because 30 workers share 10 machines.
  • Mixed environments can combine both types; nothing forbids it.

For Windows Server 2022 environments you can buy CALs individually: a Windows Server 2022 User CAL for per-person licensing or a Windows Server 2022 Device CAL for shared workstations.

Three rules that prevent expensive mistakes

  1. CALs are not tied to a server. One User CAL covers that person's access to every Windows Server in your organization, whether you run one server or twenty.
  2. CAL version must match or exceed the server version. A 2022 CAL is valid for 2022, 2019 and 2016 servers. A 2016 CAL is not valid for a 2022 server.
  3. External website visitors do not need CALs. Anonymous public access through IIS is exempt. CALs cover authenticated employees, contractors and known users.

What about Remote Desktop?

Standard CALs cover normal network access. The moment users open full desktop sessions or published apps through Remote Desktop Services, they additionally need RDS CALs. That is a separate license on top of the base CAL, and we cover it in detail in our RDS CAL guide on this blog.

Quick sizing example

A 12-person company where everyone works on a personal laptop and also checks email on a phone: 12 User CALs. The same company adds 2 shared reception PCs used by rotating staff: still 12 User CALs, because the staff members are already licensed as users. You only add Device CALs for machines used by people who have no User CAL.

Browse all CAL packs by version in the Windows Server CAL category, and if you are unsure which combination is cheapest for your headcount, message us through the contact page. Sizing CALs takes us a few minutes and costs nothing.

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