Licensing guide
What is a Windows Server CAL? User vs Device CALs explained
What a CAL is
CAL stands for Client Access License. The server licence, bought per core, gives you the right to run Windows Server. A CAL gives people or devices the right to use its services, such as file sharing, printing or authentication.
Under Microsoft licensing terms, all access to server software requires CALs. The exception is the Essentials edition, which includes client access licences. For the wider background on licensing the server itself, see Windows Server license.
User CAL vs Device CAL
| Feature | User CAL | Device CAL |
|---|---|---|
| What it permits | One user, using any device | One device, used by any user |
| What you count | People who access the server | Computers and other devices that connect to the server |
| Usually cheaper when | Staff have several devices (laptop, phone, tablet) | Many people share the same workstations, for example in shifts |
| Version | Same as or newer than the server | Same as or newer than the server |
For Windows Server 2019 we offer 1 User CAL, 10 User CALs, 1 Device CAL and 10 Device CALs.
Two worked examples
Example 1. A company has 12 employees, but they work in shifts and share 5 computers between them. Each computer connects to the server and different people use it. You need 5 Device CALs, which is fewer than 12 User CALs.
Example 2. A company has 8 employees, and each connects to the server from their own laptop and phone, so 16 devices in total. You need 8 User CALs, which is fewer than 16 Device CALs.
Rule of thumb: count the people and count the devices, then choose the CAL type that needs fewer licences. Our Windows Server license calculator applies the same rule.
How to choose the CAL type
Start with an inventory: how many users have an account with access to the server, and how many devices actually connect to it. If the numbers are similar, the way your team works can decide. User CALs are convenient when people switch devices or work remotely from several machines, because the licence follows the person. Device CALs are convenient when workstations are shared, for example in a warehouse, at a reception desk or across shifts, because the licence stays with the device.
Leave room for growth. A new employee or a new workstation means another access licence, so it is easier to plan for extra CALs than to discover a gap during an audit.
Special cases
Standard CALs do not cover every situation. Three exceptions are worth knowing:
- RDS CAL. When the server hosts a graphical user interface through Remote Desktop Services, you also need an RDS CAL, bought in addition to the base CAL.
- External Connector. Access by external users, outside your organisation, is covered by a separate External Connector licence.
- Essentials edition. Windows Server 2019 Essentials includes, according to Microsoft, CALs for up to 25 users and 50 devices. You do not buy standard CALs within that limit.
Version 2019 and its support
A Windows Server 2019 CAL makes sense if you run a 2019 server. Microsoft ended mainstream support for it on 9 January 2024. Extended support, which includes security updates, runs until 9 January 2029. After that date version 2019 will no longer receive security updates. The perpetual licence itself does not expire, but support does.
Planning a newer server? Then the CAL must be of the server version or newer. We do not offer newer server versions.
Frequently asked questions
Short answers to the questions we hear most often.
Do I always need CALs for Windows Server?
Yes, all access to server software requires CALs. The exception is Windows Server 2019 Essentials, which includes licences for up to 25 users and 50 devices.
Does a User CAL cover several devices?
Yes. One User CAL permits one user to use the server from any device.
Does a Device CAL cover several people?
Yes. One Device CAL permits one device, used by any user, to access the server.
Is a 2019 CAL enough for a 2022 server?
No. The CAL must be the same version as the server or newer. An older CAL does not cover a newer server.
Does an RDS CAL replace a normal CAL?
No. An RDS CAL is additional. Access to the server still requires the base CAL.
How many CALs do I need for 20 employees?
Count the people and the devices that connect, and use the smaller number. With 20 people and one device each the numbers are equal, so the choice of type is a matter of convenience.
Legal basis and sources
We checked licensing rules and support dates against official documents. Links open the publishers’ pages.
Licences for your company?
Business account, quotes on request and invoices in your customer panel.
