RDS CAL Licensing Guide 2026: Windows Server 2025 User vs Device CALs

In short

RDS CAL licensing applies when users or devices access Windows Server through Remote Desktop Services (RDS), such as an RD Session Host delivering shared desktops or RemoteApp programs. For customer-owned Windows Server deployments, Microsoft offers RDS User CALs and RDS Device CALs. These are separate from the underlying Windows Server license and from the ordinary Windows Server CALs that may also be required under the customer's licensing model.

For Windows Server 2025, use RDS CAL rights that cover Windows Server 2025. A newer RDS CAL can cover an older session host, but an older RDS CAL does not cover a newer Windows Server session host. Microsoft also requires the RD Licensing server to run the same Windows Server version as the CAL pack or a later version.

A newly created RD Session Host has a 120-day technical licensing grace period. That window is for deployment and configuration; it should not be treated as a substitute for valid commercial licensing.

If Raff provides the Windows workload under its hosted SPLA model, the access model is different: hosted RDS uses RDS SALs (Subscriber Access Licenses) rather than asking the customer to bring ordinary RDS User or Device CALs. For broader Windows Server SPLA, BYOL, evaluation, and outsourcing guidance, see Windows Server Licensing on Raff.

RDS CAL licensing: what you actually need

The licensing question starts with the workload, not the RDP client.

The two built-in administrative connections are not “two free employee licenses.” If staff use the server as a shared workplace, design it as an RDS workload.

For the architecture decision, read Multi-User RDP: 2 Admin Sessions vs RDS Session Host.

What is an RDS CAL?

An RDS Client Access License (RDS CAL) gives a user or device the right to access Remote Desktop Services functionality on Windows Server under Microsoft's customer licensing model.

Microsoft provides two licensing modes:

• Per User — a CAL is assigned to a user, who can access the RDS environment from multiple devices.
• Per Device — a CAL is assigned to a device, which can be used by multiple users.

The RD Session Host is configured for one licensing mode, and the RD Licensing server issues or tracks the appropriate licenses.

Windows Server CAL vs RDS CAL

An RDS CAL does not replace the underlying Windows Server access license.

In Microsoft's normal customer-owned Windows Server licensing model, the stack can look like this:

Windows Server license
+
Windows Server CAL for applicable users/devices
+
RDS CAL for users/devices that use Remote Desktop Services

The exact Windows Server CAL requirement depends on the customer's Microsoft agreement and licensing program. The important point is that RDS CALs are additive rights for RDS functionality, not substitutes for the base Windows Server licensing model.

Hosted SPLA services use a different service-provider licensing model and should not be mixed conceptually with customer CALs.

Windows Server 2025 RDS CAL requirements

For an RD Session Host running Windows Server 2025, use RDS CAL rights that cover Windows Server 2025.

Microsoft's compatibility rule is straightforward:

• a newer RDS CAL can access the same or an older Windows Server version;
• an older RDS CAL cannot access a newer Windows Server version;
• the RD Licensing server must run the same Windows Server version as the installed RDS CAL pack or a later version.

That means a Windows Server 2025 RDS CAL can cover a Windows Server 2022 or 2019 session host, but a 2022 RDS CAL does not cover a Windows Server 2025 session host.

Likewise, a Windows Server 2022 license server cannot host a Windows Server 2025 RDS CAL pack. Use a Windows Server 2025 or later licensing server for 2025 CALs.

RDS User CAL vs Device CAL

Choose the licensing mode based on how people actually access the environment.

Choose Per User when

• each employee has a distinct identity;
• users may connect from multiple devices;
• the RDS deployment is domain-joined;
• licensing by person matches the workforce better than licensing endpoint devices.

Choose Per Device when

• several people share a smaller number of devices;
• the environment uses kiosks or shift workstations;
• the deployment is a Windows workgroup rather than Active Directory.

Do not select the mode only because one appears cheaper in a reseller catalog. Count real users and real connecting devices first.

Workgroup RDS must use Per Device licensing

Microsoft's current guidance distinguishes domain-joined and workgroup deployments.

A domain-joined RD Session Host can use Per User or Per Device licensing. A workgroup RD Session Host must use Per Device licensing; Per User mode is not permitted for the workgroup scenario.

Microsoft has also tightened authentication requirements between workgroup RD Session Hosts and RD Licensing servers through security updates. Do not weaken licensing-server authentication to preserve an old configuration. If a small workgroup deployment is becoming a larger multi-user service, review whether an Active Directory-backed design is now more appropriate.

RDS CAL version compatibility table

The same-versus-newer rule also matters on the license server side: the license server OS must be the same version as the CAL pack or newer.

The 120-day RDS grace period

Microsoft provides a 120-day licensing grace period for a newly created RD Session Host. During that technical window, the session host can accept RDS connections before an RD Licensing server is fully configured.

Before the grace period ends, a customer-owned CAL deployment should have:

1. an activated RD Licensing server;
2. a valid RDS CAL pack installed;
3. the RD Session Host pointed to the correct license server;
4. the licensing mode set to Per User or Per Device as appropriate.

Once the grace period expires, licensing misconfiguration can cause users to receive Remote Desktop licensing errors and prevent normal RDS access.

The grace period is not a commercial licensing loophole. Contractual Microsoft licensing obligations are separate from the technical timer in Windows Server.

How to configure RDS licensing at a high level

For a customer-owned RDS deployment, the high-level sequence is:

1. Install the Remote Desktop Licensing role service.
2. Open Remote Desktop Licensing Manager and activate the license server.
3. Install the appropriate RDS CAL pack.
4. Configure the RD Session Host licensing mode.
5. Configure which license server the session host should use.
6. Validate the configuration before the grace period expires.

Microsoft documents the supported configuration process in License Remote Desktop Session Hosts.

For a production deployment, follow Microsoft's current role and licensing guidance rather than copying registry changes from old forum posts.

How to check if RDS is licensed

When troubleshooting, verify the whole licensing chain rather than only checking whether an RDP session opens.

Check:

• the RD Licensing role is installed where expected;
• the license server is activated;
• the correct RDS CAL pack is installed;
• the CAL version covers the RD Session Host version;
• the Session Host is configured for the intended Per User or Per Device mode;
• the Session Host is configured to use the intended license server;
• the Session Host can resolve and reach the license server;
• RD Licensing Diagnoser does not report licensing configuration errors.

You can also inspect the installed role state with PowerShell:

Get-WindowsFeature RDS-Licensing, RDS-RD-Server | Format-Table Name, InstallState

A working session during the 120-day grace period does not prove that production licensing is configured correctly.

How much does an RDS CAL cost?

There is no single permanent RDS CAL price that is safe to hard-code into a licensing guide.

Pricing varies by:

• Windows Server generation;
• User versus Device CAL;
• pack size;
• reseller or Microsoft sales channel;
• geography and currency;
• commercial agreement and volume program;
• taxes and promotions.

Microsoft currently lists Windows Server 2025 Remote Desktop Services CAL products through its official Store, and authorized resellers list individual and multi-license packs. Because those prices can change, use the current Microsoft Store or your authorized licensing reseller for a purchase quote.

If you are evaluating Raff-hosted licensing, do not compare a retail RDS CAL price directly with hosted SPLA. The licensing unit is different: SPLA-hosted RDS uses RDS SALs, and the service price should be confirmed for the actual hosted deployment.

Does Windows Server 2025 include RDS CALs?

No. Buying or licensing Windows Server 2025 does not automatically provide the RDS CALs needed for RD Session Host users or devices in a customer-owned licensing model.

Think of them as separate layers:

Windows Server licensing
→ allows the Windows Server workload

Windows Server CALs where applicable
→ allow users/devices to access the server software

RDS CALs
→ add the right to use Remote Desktop Services functionality

For a hosted SPLA service, Microsoft uses the provider's service-provider licensing model instead.

Does RDP require an RDS CAL?

Not every use of the RDP protocol requires an RDS CAL.

Microsoft permits two concurrent Remote Desktop connections for Windows Server administration without RDS CALs. Those connections are for administrators managing the server.

If employees use RD Session Host for shared desktops or RemoteApp programs, the applicable RDS licensing model is required.

This distinction is why changing an RDP connection limit does not turn administrative Remote Desktop into a properly licensed multi-user desktop service.

Customer RDS CALs vs hosted RDS SALs

This is the most important distinction for Raff customers.

Do not describe SPLA SALs as ordinary customer CALs. The underlying rights, reporting, and commercial model are different.

For Raff, confirm the hosted Windows and RDS licensing configuration during onboarding. For customer-owned licenses, confirm the customer's entitlement and outsourcing rights with its Microsoft licensing reseller or licensing specialist.

For the wider Windows Server licensing decision, see Windows Server Licensing on Raff.

BYOL and RDS CALs: avoid the License Mobility shortcut

Older cloud guidance often says that bringing Microsoft licenses to a hosting provider universally requires “Software Assurance + License Mobility.” That is too broad for Windows Server and RDS planning.

Windows Server is not an ordinary License Mobility through Software Assurance product. Modern customer-hosted scenarios can involve Microsoft outsourcing rights and the Flexible Virtualization Benefit, depending on the exact subscription/license, Software Assurance status, provider, and customer agreement.

RDS access rights also depend on the customer's licensing agreement and deployment model. Do not assume a standard License Mobility verification form is the universal path for RDS CAL use on hosted Windows Server.

If you want to bring customer-owned Windows Server and RDS licenses to Raff, verify the exact entitlement with a Microsoft licensing specialist or reseller before production deployment.

Can RDS CALs be moved to another server?

There are two separate ideas that are often mixed together:

1. Moving or rebuilding the RD Licensing server. CAL packs can be reinstalled or migrated through Microsoft's supported activation/licensing process when a license server is replaced.
2. Reassigning the underlying user/device entitlement. Reassignment rights and timing depend on the applicable Microsoft licensing terms and agreement.

Do not treat migration of the license-server role as proof that every license can be freely reassigned at any time. If you are replacing a licensing server or moving a licensed workload between providers, confirm both the technical migration steps and the contractual rights.

Common RDS licensing errors

The grace period expired

Symptoms can include Remote Desktop licensing warnings or rejected user sessions. Configure and activate the RD Licensing server, install valid licenses, and verify that the Session Host is using the correct server and mode.

The CAL version is too old for the Session Host

A Windows Server 2022 RDS CAL does not cover a Windows Server 2025 RD Session Host. Use rights that cover the host version.

The license server OS is too old for the CAL pack

A Windows Server 2022 license server cannot host a Windows Server 2025 RDS CAL pack. Upgrade or deploy a license server on Windows Server 2025 or later.

Workgroup deployment configured for Per User

Workgroup RDS requires Per Device licensing. Change the design to the supported model rather than forcing Per User behavior.

Session Host cannot find the license server

Check DNS resolution, firewall/network connectivity, configured license-server name, and RD Licensing Diagnoser.

The server is in the wrong licensing mode

A Per User CAL pack does not help if the Session Host is configured for Per Device, and vice versa. Confirm the intended mode across the deployment.

Administrative RDP is being used as an employee desktop workaround

The two administrative connections are for server administration. If employees need daily Windows sessions, deploy and license RD Session Host properly.

RDS CAL licensing checklist

Before putting a customer-owned RD Session Host into production, confirm:

• The Windows Server version is documented.
• The customer licensing model is documented.
• The RDS licensing mode is Per User or Per Device by design.
• Workgroup deployments use Per Device.
• The RDS CAL generation covers the Session Host version.
• The RD Licensing server version can host the CAL pack.
• The licensing server is activated.
• The CAL pack is installed.
• The Session Host points to the correct license server.
• RD Licensing Diagnoser shows no unresolved licensing errors.
• The 120-day grace period is not being used as the production licensing plan.
• Customer CAL licensing is not being confused with hosted SPLA SAL licensing.

Frequently asked questions

What is an RDS CAL?

An RDS CAL is a Microsoft Client Access License that grants a user or device the right to use Remote Desktop Services functionality on Windows Server under the customer licensing model.

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

A User CAL is assigned to a person and is usually better when that person connects from several devices. A Device CAL is assigned to a device and is usually better when several users share the same workstation. Workgroup RDS deployments must use Per Device.

How much does a Microsoft RDS CAL cost?

The price varies by Windows Server version, User or Device type, pack size, geography, sales channel, and commercial agreement. Check Microsoft's current Store listing or an authorized reseller rather than relying on an old tutorial price.

Does Windows Server 2025 come with RDS CALs?

No. RDS CALs are separate access rights for Remote Desktop Services in a customer-owned licensing model.

Does RDP require an RDS CAL?

Two concurrent administrative Remote Desktop connections can be used to administer Windows Server without RDS CALs. RD Session Host user sessions require the applicable RDS licensing model.

How do I check if RDS is licensed?

Verify the activated RD Licensing server, installed CAL pack, CAL version, configured licensing mode and license-server assignment, then review RD Licensing Diagnoser for errors.

Can Windows Server 2025 RDS CALs be used with Server 2022 or 2019?

Yes. Newer RDS CALs can cover older compatible Windows Server session hosts. The reverse is not true: older CALs do not cover newer Session Hosts.

What happens after the 120-day RDS grace period?

If the RD Session Host is not properly configured with a valid licensing server and applicable licenses, users can receive Remote Desktop licensing errors and normal RDS access can be blocked.

What is the difference between an RDS CAL and an RDS SAL?

RDS CALs are used in Microsoft's customer licensing model. RDS SALs are used by service providers under SPLA for hosted RDS services. Raff-hosted SPLA deployments should be evaluated as SAL-based services rather than ordinary customer CAL deployments.

What's next

• Multi-User RDP: 2 Admin Sessions vs RDS Session Host
• Windows Server Licensing on Raff
• Windows Server 2019 vs 2022 vs 2025
• Windows VPS Sizing for Remote Users
• Raff Windows VM

Sources

• Microsoft Learn — License Remote Desktop Services with Client Access Licenses (CALs)
• Microsoft Learn — License Remote Desktop Session Hosts
• Microsoft Learn — Troubleshoot Remote Desktop disconnected errors
• Microsoft Licensing — Windows Server Product Terms
• Microsoft Store — Windows Server 2025 Remote Desktop Services CALs
• Sources verified: 2026-08-28

Microsoft licensing terms can vary by agreement, program, product version, geography, and deployment model. Microsoft Product Terms and the customer's executed licensing agreement control if they conflict with this guide.