Windows Server 2025 RDS CAL Guide: User vs Device CALs, Cost, Grace Period

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 deployments, Microsoft offers RDS User CALs and RDS Device CALs.

For Windows Server 2025, the CAL generation must cover Windows Server 2025. A 2022 RDS CAL does not cover a 2025 Session Host, while a 2025 CAL can cover compatible older hosts. A newly created RD Session Host also receives Microsoft's 120-day technical grace period.

For Raff-hosted RDS, the licensing model is different: Raff uses Microsoft SPLA and RDS Subscriber Access Licenses (SALs). The current Raff RDS SAL price is $8 per authorized unique user per month. For the broader Windows licensing model, 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: assigned to a user, who can access the RDS environment from multiple devices.
• Per Device: 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 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 model and should not be mixed conceptually with customer CALs.

Windows Server 2025 RDS CAL requirements

A Windows Server 2025 RDS CAL is required for each applicable user or device that accesses an RD Session Host running Windows Server 2025 under Microsoft's customer CAL model.

Microsoft's version-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 2022 RDS CAL does not cover a Windows Server 2025 Session Host, while a 2025 RDS CAL can cover compatible 2022 or 2019 Session Hosts.

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.

If a small workgroup deployment is becoming a larger multi-user service, review whether an Active Directory-backed design is now more appropriate rather than trying to force unsupported Per User behavior.

RDS CAL version compatibility table

Before buying CALs, check the Windows Server support lifecycle for every Session Host you plan to keep in service.

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. The same is true for Raff-hosted SPLA: the Windows grace-period mechanism does not create 120 days of free hosted-user licensing.

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.

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 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 retail RDS CAL price that is safe to hard-code into a licensing guide.

Customer CAL pricing varies by Windows Server generation, User versus Device CAL, pack size, reseller or Microsoft sales channel, geography, currency, agreement, taxes, and promotions. Use Microsoft's current Store listing or an authorized licensing reseller for a purchase quote.

Raff-hosted RDS uses a different commercial model. The current Raff RDS User SAL is $8/month per authorized unique user under the hosted SPLA service model.

See Remote Desktop hosting on Raff.

This is not a concurrent-session price. If ten people are authorized to use the hosted RDS environment during a month, plan ten SALs even if only three are normally connected at the same time.

Raff-hosted RDS cost examples

For a Raff-hosted Windows Server environment, budget the Windows VM and RDS SALs separately.

A 2 vCPU / 4 GB / 80 GB Windows VM currently costs $37.99/month total, including the $15 Windows Server Standard SPLA charge. RDS SALs are then added for the authorized users.

*Illustrative VM + Windows Server + RDS SAL total only. Real RDS workloads may require more CPU/RAM, additional storage, backups, Microsoft 365 licensing, application licensing, SQL Server licensing, or a separate RD Gateway/identity design.

For sizing, use Windows VPS Sizing for Remote Users. For current infrastructure pricing, see Raff Windows VM and pricing.

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.

Customer RDS CALs vs hosted RDS SALs

This is the most important distinction for Raff customers.

For Raff-hosted RDS, the current RDS User SAL price is $8 per authorized unique user per month. Microsoft SPLA licensing counts authorized users, not just peak concurrent sessions.

If you are hosting QuickBooks on a server for a remote team, each person authorized to use the hosted RDS service needs the applicable CAL or hosted SAL rights in addition to the application's own licensing.

BYOL and RDS CALs: what outsourcing rights actually cover

Windows Server licensing on third-party infrastructure depends on the customer's exact entitlement, Software Assurance or subscription rights where applicable, the provider relationship, and the Flexible Virtualization Benefit rules that apply to eligible Windows Server licenses.

RDS access rights also depend on the customer's licensing agreement and deployment model. Do not assume that customer-owned Windows Server or RDS rights can simply be moved to any hosted environment without checking the applicable outsourcing terms.

For Windows Server BYOL, Flexible Virtualization Benefit and outsourcing rights are the relevant concepts. License Mobility through Software Assurance is not the Windows Server BYOL mechanism; it applies to eligible server applications such as SQL Server.

If you want to bring customer-owned Windows Server and RDS rights 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 and 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.

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 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.

For Raff-hosted RDS, document the number of authorized users and include the current $8/user/month RDS SAL in the monthly cost model before onboarding users.

What's next

• Multi-User RDP: 2 Admin Sessions vs RDS Session Host
• Windows Server Licensing on Raff
• Windows Server 2025 editions and versions
• Windows VPS Sizing for Remote Users
• Remote Desktop VPS

Sources

• Microsoft Learn: https://learn.microsoft.com/en-us/windows-server/remote/remote-desktop-services/rds-client-access-license
• Microsoft Learn: https://learn.microsoft.com/en-us/windows-server/remote/remote-desktop-services/rds-license-session-hosts
• Microsoft Licensing: https://www.microsoft.com/licensing/spur/en-US/productoffering/WindowsServer/all
• Microsoft Store: https://www.microsoft.com/en-us/d/windows-server-2025-remote-desktop-services/dg7gmgf0pwhb
• Sources revalidated: 2026-09-17

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.