User CAL or device CAL: difference and decision

User CAL or device CAL? Take the type you need fewer of. A user CAL covers one person with any number of devices; it fits when employees work with a PC, laptop and smartphone. A device CAL covers one device with any number of people; it fits shift work and shared workstations. Both types give the same access rights, and you may mix them.

Quick decision

Your business	Suitable CAL
Every employee has their own devices, often several	User CAL
Working from home, access also from private or changing devices	User CAL
More devices than employees	User CAL
Shift work, several people per workstation	Device CAL
Checkouts, warehouse terminals, reception, production	Device CAL
More employees than devices	Device CAL
Office and production in the same company	both mixed

The difference

Feature	User CAL	Device CAL
Assigned to	one person	one device
Number of devices	any number per person	exactly one
Number of people	exactly one	any number per device
Access rights	the same	the same
Valid for	all your licensed Windows Servers of the same or an earlier version	all your licensed Windows Servers of the same or an earlier version
Typical use	office, field service, working from home	shifts, checkout, warehouse, medical practice

Microsoft describes the choice like this: user CALs make sense when employees access the server from several or from unknown devices or when there are more devices than users. Device CALs are economical and easier to manage when employees share devices, for example in shifts.

What a CAL is in principle and when none is needed is described in
Windows Server CAL: when you need client access licenses.

How to calculate

Count the people who access the server. This includes part-time staff, trainees and temporary staff with their own access.
Count the devices from which access takes place: PCs, laptops, thin clients, tablets, smartphones with access to server services, checkouts, scanners with a network drive.
Compare both numbers. The smaller one decides, provided the prices per CAL are similar.
Check whether the business can be divided into groups, for example office (user) and warehouse (device).

Sample calculations in license quantities:

Business	People	Devices	Result
Tax consultancy, everyone with PC and laptop	12	24	12 user CALs
Medical practice with shared reception and treatment PCs	14	8	8 device CALs
Production company: 10 in the office, 40 in three shifts at 12 terminals	50	22	10 user CALs and 12 device CALs

In the third case, a uniform solution would be 50 user CALs or 22 device CALs (10 office PCs and 12 terminals). The mix also comes to 22 but additionally covers the laptops and smartphones of the office employees.

The license calculator compares both types when you enter users and devices: it works out both totals at current prices and suggests the smaller one. If you enter only users or only devices, it calculates with that type.

Rules you should know

Assignment. A user CAL belongs to a specific person, a device CAL to a specific device. It is normally not a quota for concurrent connections: ten CALs do not cover “ten concurrent accesses” by thirty changing employees to your servers. As a one-time alternative, the product terms provide for a per server mode in which CALs are permanently assigned to a single server instance and allow that many concurrent accesses to exactly this instance. For environments with several servers, this is rarely suitable.
Indirect access. Anyone who accesses the server through an application or a portal also needs a CAL. A shared sign-in account for several people does not replace user CALs.
Mixing is allowed. Microsoft expressly permits a combination of user CALs, device CALs and External Connector licenses. Keep a list of who or what has which CAL.
Version. The type of CAL does not change the version rule: the CAL must have the version of the server or be newer, see Which CAL version fits which server.

Special points for RDS CALs

RDS CALs for Remote Desktop also come per user and per device. Here the technology comes into play, because a license server issues the RDS CALs. Microsoft names these differences:

Feature	RDS CAL per device	RDS CAL per user
Assignment	permanently assigned to the device	to a user in Active Directory
Tracking without Active Directory	possible	not possible in a workgroup
Overallocation	technically not possible	technically possible, but a license violation
Typical use	shift work on shared computers	every user with their own devices

It is usual to buy Windows Server CALs and RDS CALs of the same type. The license calculator does the same: the RDS CALs follow the type of the Windows Server CALs. More on this in
RDS CAL: licensing Remote Desktop Services.

Typical cases

Office with 12 workstations and working from home. Every employee uses an office PC and a private laptop. 12 user CALs. With device CALs you would have to count every device, including the private ones.

Retail store with 4 checkouts and 15 temporary staff. 4 device CALs for the checkouts. The owner, who additionally accesses the server from home, gets a user CAL.

Care service with 30 staff and 6 ward PCs. 6 device CALs. If the care staff later also access the server by tablet, the calculation tips: then the tablets have to be counted too.

Terminal server for 25 employees with their own thin clients. 25 users and 25 devices give the same number. User CALs are more flexible here because they also cover access from a second device: 25 user CALs and 25 RDS user CALs.

At VivaKeys

All client access licenses are in the CALs category. How the server side is counted is explained in
Licensing Windows Server: cores, VMs, CALs.

Frequently asked questions

What is the difference between a user CAL and a device CAL? The user CAL licenses one person for any number of devices, the device CAL one device for any number of people. The access rights are the same.

Can I mix user CALs and device CALs? Yes. Microsoft allows the combination. It makes sense when one part of the business has its own devices and another part shares devices.

What does user CAL mean? CAL stands for client access license. The user CAL is the client access license for one user to a server, here Windows Server.

What is the difference between a user CAL and an RDS CAL? The user CAL for Windows Server allows access to the server. The RDS CAL additionally allows Remote Desktop sessions. For a terminal server you need both.

Does a device CAL also cover smartphones and tablets? A device CAL covers exactly one device. Every further device that accesses the server needs its own device CAL, unless the user has a user CAL.

Are user CALs and device CALs different for Windows Server 2025 and 2022? The types are the same, the version differs. 2025 CALs are valid for Windows Server 2025 and earlier versions, 2022 CALs only up to Windows Server 2022.

Sources

Checked on 2026-11-10 against the publisher’s information:

User CAL or device CAL