An RDS CAL (Remote Desktop Services Client Access License) is a Microsoft license that gives a user or device the right to connect to a Windows Server running the Remote Desktop Session Host (RDSH) role. Every person or device that connects to a remote desktop session needs one. Without valid RDS CALs in place, remote desktop connections stop working once the server’s built-in grace period expires. RDS CALs are available for Windows Server 2025, 2022, 2019, and 2016.

This is a common point of confusion. You typically need both a Windows Server CAL and an RDS CAL. A Windows Server CAL lets a user or device access the server network, such as file, print, or DNS services. An RDS CAL is specifically required when a user or device initiates a Remote Desktop session to interact with the graphical interface or run applications remotely. If you are using Remote Desktop Services, you technically need an RDS CAL for each user or device.

Yes. “Terminal Services CAL” is the older name used before Windows Server 2008 R2. When Microsoft rebranded Terminal Services to Remote Desktop Services, the license name changed too. An RDS CAL and a Terminal Services CAL refer to the same license type. If you see references to “TS CAL” in older documentation, it means the same thing as an RDS CAL.

An RDS CAL is a perpetual one-time purchase license. An RDS SAL (Subscriber Access License) is a monthly subscription alternative, typically available only through Microsoft service providers authorized to use SPLA. For most organizations running their own servers, RDS CALs are the standard option. RDS SALs are primarily used by hosting providers offering RDS as a managed service.

Yes. If Citrix, Parallels RAS, or another third-party solution connects users to a Windows Server running the RDSH role, RDS CALs are still required. The licensing requirement comes from Microsoft and applies regardless of which software brokers the remote desktop connection. The third-party tool does not replace or include the RDS CAL.

It depends on what you are virtualizing. If your VDI environment runs Windows Server desktops through the RDSH role, then you need RDS CALs. If you are running Windows 10 or Windows 11 virtual desktops without RDS, you do not need RDS CALs, but you will need Windows VDA licenses or eligible Microsoft 365 subscriptions instead. If you use RDS to deliver Windows client desktops, you may need both.

Standard RDS CALs are perpetual licenses and do not require monthly or annual renewal. Once purchased, they remain valid for the supported lifetime of the Windows Server RDS version they are purchased for, including eligible downgrade use.

A Per-User RDS CAL is assigned to an individual person through their Active Directory user account. Once licensed, that person can connect to the RDS environment from an unlimited number of devices, such as an office desktop, laptop, tablet, phone, or home computer. This is the most popular option for organizations with remote and hybrid workers.

A Per-Device RDS CAL is assigned to a specific physical device, such as a computer, thin client, kiosk, or workstation. Once that device is licensed, any number of users can log in through it to access Remote Desktop Services. The license stays with the machine, not the person. This is the standard choice for shared workstations, shift-based environments, and labs.

Count your users and count your devices, then license whichever number is smaller. Choose User CALs when employees work from multiple devices. One license per person covers everything. Choose Device CALs when multiple people share a single workstation, such as shift workers, shared terminals, kiosk machines, or lab computers. One license per machine covers every user.

For Per-User CALs, count every unique person who will ever connect to your RDS environment, not just concurrent users. Even if someone only connects once a month, they need their own CAL. For Per-Device CALs, count every physical device that will connect. If you have 30 workstations that access RDS, you need 30 Device CALs, regardless of how many people use those workstations.

Yes. Microsoft allows you to run both Per-User and Per-Device RDS CALs on the same Remote Desktop Session Host simultaneously. Many organizations use a mix to optimize costs, such as Per-User CALs for remote workers and Per-Device CALs for shared kiosks or lab machines.

Yes. Per-User RDS CALs are tracked through Active Directory user accounts. While it is technically possible to install Per-User CALs in a workgroup, the license server cannot properly track user-based licensing in that configuration. If your Windows Server is in a workgroup without Active Directory, use Per-Device CALs instead.

Yes. Per-Device CALs function correctly in both workgroup and domain-joined environments. The license server tracks devices by their unique hardware identifier, which does not depend on Active Directory. This makes Per-Device CALs the recommended choice when there is no domain controller present.

If you purchase the wrong CAL type, you can exchange eligible unactivated licenses from your account dashboard within 60 days of purchase. Go to your Order Summary, choose the correct product, and pay any applicable price difference. Once the exchange is completed, the original license key is permanently blacklisted to prevent unauthorized use.

Yes. Higher-version RDS CALs include downgrade rights for earlier supported Windows Server RDS deployments. For example, Windows Server 2025 RDS CALs can be used with Windows Server 2025, 2022, 2019, and 2016 RDS environments. Windows Server 2022 RDS CALs can be used with Windows Server 2022, 2019, and 2016. Windows Server 2019 RDS CALs can be used with Windows Server 2019 and 2016. Older RDS CALs cannot be used with newer Windows Server versions.

No. Older CALs cannot be used with a newer server version. To connect to a Windows Server 2025 Session Host, you must have Windows Server 2025 RDS CALs. This is a Microsoft licensing requirement with no workaround.

No. The RD Licensing Server must be running the same Windows Server version or newer than the CALs you want to install. A Windows Server 2019 License Server cannot recognize or install Windows Server 2025 RDS CALs. You need a License Server running Windows Server 2025 or later to install 2025 CALs.

Yes. RDS CALs are not edition-specific. The same CAL works with Standard, Datacenter, and Essentials editions of Windows Server. The main requirement is that the CAL version matches or exceeds the server version.

No. RDS CALs are not tied to a specific server. A single Per-User or Per-Device CAL covers access to any Remote Desktop Session Host in your environment, as long as all Session Hosts are running the same or an older Windows Server version as the CAL. You install your CALs on a central RD Licensing Server, and it manages issuance to all Session Hosts across your farm.

Yes. RDS CALs are installed on a centralized RD Licensing Server, not on individual Session Hosts. When a user or device connects to any Session Host, that host contacts the Licensing Server to request a CAL. One pool of licenses serves the entire RDS infrastructure, so there is no need to buy separate CALs for each server.

Pricing depends on the server version, pack size, and CAL type. User and Device CALs are priced identically. Larger packs offer better per-CAL value. Pricing for Windows Server 2025, 2022, 2019, and 2016 versions varies.

No. An RDS CAL is an access license only. It does not include the Windows Server operating system. You must have a separately licensed copy of Windows Server Standard or Datacenter with the RDSH role installed before RDS CALs can be deployed.

An RD Licensing Server is a Windows Server role that stores, issues, and tracks your RDS CALs. It must be installed and activated with the Microsoft Clearinghouse before it can issue licenses. When a user or device connects to a Session Host, the Session Host contacts the Licensing Server to check for a valid CAL before granting access.

Yes. For small deployments or single-server setups, both the RD Session Host and RD Licensing roles can be installed on the same server. For larger environments with multiple Session Hosts, a dedicated physical or virtual Licensing Server is recommended for easier management.

After installing the RD Licensing role through Server Manager, open the Remote Desktop Licensing Manager and right-click your server to begin activation. The Automatic Connection method contacts the Microsoft Clearinghouse over the internet. If your server has no internet access, use the Web Browser method instead, which lets you complete activation from a separate machine.

Once the RD Licensing Server is activated, open the Remote Desktop Licensing Manager, right-click the server, and select Install Licenses. Enter your product key or License Agreement Number when prompted and follow the wizard. The CALs become available for issuance immediately after installation.

The licensing mode must match the type of CALs you installed. Set this through Server Manager under Remote Desktop Services deployment properties, or through Group Policy under Remote Desktop Session Host licensing settings. A mismatch between the configured licensing mode and installed CAL type can cause licensing errors.

Yes. A single RD Licensing Server can issue CALs to multiple Session Hosts across your network. This is the recommended setup because centralizing license management simplifies tracking. The Licensing Server can serve Session Hosts across Active Directory domains, forests, and workgroup environments.

When you install the Remote Desktop Session Host role on a Windows Server, Microsoft provides a 120-day grace period. During this window, remote desktop connections work without an RD Licensing Server or installed CALs. Once the 120 days expire, all remote connections except the two built-in admin sessions are blocked until valid CALs are deployed.

Temporary CALs are specific to the Per-Device licensing model. The first time a new device connects to the Session Host, the license server issues a temporary CAL valid for 52 to 89 days. When the device connects a second time, the license server upgrades it to a permanent Per-Device CAL, provided permanent CALs are available.

No. The Per-User model does not use temporary CALs. The license server grants a license directly from the available pool. Per-User CALs show an expiration date of 60 days after issuance, but they are automatically renewed each time the user connects, so the license remains active as long as the user is accessing the environment.

It depends on the type. Per-Device CALs can be manually revoked up to 20% of your total issued CALs using the Remote Desktop Licensing Manager console. This is useful when a device is replaced or retired. Per-User CALs cannot be manually revoked; they return to the available pool automatically when the user no longer connects.

If the device no longer connects to the RDS environment, its assigned CAL will expire naturally after 52 to 89 days and return to the available pool. If you need the license back immediately, you can use the 20% revocation allowance in the Licensing Manager.

Yes. These RDS CALs can be moved to another server when you replace or upgrade your server hardware. To remain compliant, the original server should be fully decommissioned or wiped before the licenses are activated on the new deployment.

Open the Remote Desktop Licensing Manager on your RD Licensing Server. It shows the total number of installed CALs, how many have been issued, and how many remain available. For Per-Device CALs, you can see individual device assignments. For Per-User CALs in an Active Directory environment, you can generate reports showing which users have been issued licenses.

Yes. You can purchase additional CAL packs at any time and install them on your existing RD Licensing Server alongside your current licenses. The new CALs are immediately added to your available pool. There is no limit to how many times you can expand your license count.

No. Windows Server includes two concurrent administrative remote desktop sessions at no additional license cost. These are intended strictly for server management and maintenance tasks. If administrators use these sessions to run business applications, such as Office, ERP, or CRM software, RDS CALs are required for those sessions.

If you are only using the two built-in administrative sessions for server management, no RDS CAL is required. The moment you enable the Remote Desktop Session Host role for additional users or devices, or use admin sessions for day-to-day business applications, RDS CALs become necessary.

Yes. Any user connecting to your RDS environment requires an RDS CAL, regardless of whether they are an employee, contractor, client, or partner. There is no exemption for external users. For a large number of external users, Microsoft also offers an External Connector license as an alternative to individual CALs.

Yes. If you are running a Windows Server instance in Azure with the RDSH role enabled, you still need RDS CALs. Azure covers the base Windows Server license, but the RDS CAL is an additional requirement. Only Per-User RDS CALs can be used in Azure; Per-Device CALs are not permitted in cloud deployments.

Only Per-User RDS CALs can be used on Azure.

No. Azure Virtual Desktop runs on Windows 10/11 multi-session and does not use the Remote Desktop Session Host role on Windows Server. Because of this, RDS CALs are not required for AVD.

RDS CALs are sold in packs of 5, 10, 20, and 50, available in both User and Device variants for Windows Server 2025, 2022, 2019, and 2016. You can purchase multiple packs and install them on the same license server. For example, two 50-User packs give you 100 User CALs.

RDS CALs are fully digital products. There is no physical media or shipping involved. Your license details and setup instructions are delivered by email within 15 minutes after successful checkout. A copy will also be available in your account dashboard under Order Summary for future reference.

Your license details and setup instructions are delivered by email within 15 minutes after successful checkout. A copy will also be available in your account dashboard under Order Summary.

No. Our RDS CALs are approved for worldwide deployment and are not region-restricted. You can install and deploy these licenses on servers located anywhere in the world.

You receive license details for your records, setup instructions, and links to helpful installation guides. Your license details and setup instructions are delivered by email within 15 minutes after successful checkout, and a copy will also be available in your account dashboard under Order Summary for future reference.

This error means the Session Host cannot communicate with the RD Licensing Server. Check whether the RD Licensing Server is activated, whether the Session Host is pointed to the correct Licensing Server, whether any firewall is blocking communication, and whether the Remote Desktop Licensing service is running on the Licensing Server.

The 120-day grace period has expired and no valid RDS CALs are available. To fix this, install and activate an RD Licensing Server, add your CALs, and configure your Session Host to point to it. Connections will resume once valid CALs are in place.

Your RD Licensing Server needs to be activated with the Microsoft Clearinghouse before it can issue CALs. Open the Remote Desktop Licensing Manager, right-click your server name, and select Activate Server. If the automatic method fails because the server has no internet access, use the Web Browser or Telephone method instead.

Check three things: licensing mode mismatch, wrong license server, and CAL availability. Make sure the licensing mode configured on the Session Host matches the type of CALs installed, verify the Session Host points to the correct RD Licensing Server, and confirm the CALs show as available in Licensing Manager.

The RD Licensing Server can only install CALs for its own Windows Server version or older. If the Licensing Server is running Windows Server 2019, it will not show options for Windows Server 2022 or 2025 CALs. The fix is to set up a new License Server running the same Windows Server version as the CALs you need to install.

Microsoft does not support or recommend resetting the grace period. It is a one-time window intended to give you time to set up licensing. The proper solution is to install valid RDS CALs before the grace period expires.