CAL-culating Client Access Licensing

By on July 9, 2018 in 


Your organization just launched a Microsoft SQL Server and now you can finally get the data you need when and where you need it. With all the excitement that mountains of data naturally brings, you rush to the nearest terminal and attempt to access the new server only to be crushed by denial due to insufficient CAL licensing. What?!? What is a CAL? Why do you need one if you have already purchased the software/operating system? This article will simplify the often unknown licensing method of Client Access Licenses.


Basically a Client Access License, or CAL, is Microsoft’s way of allowing for public versions of their proprietary software/operating systems to be controlled. In our interconnected world we have grown accustom to having our technology being always available and accessible, so we created networks and online instances to increase that access. Microsoft has come up with three main types of licenses that go along with this desire to access our applications in any and every way imaginable. Basically they will allow you to authorize a person or device to access the application, or in applicable instances allow hardware to host it. Here are the three main types of licenses:

  • User CAL – Authorizes a single individual user access to the software/OS from any number of devices so long as only one device is connected at a time. This is much like a web app would have a login that is unique to an individual.
  • Device CAL – This license type gives authorization to one specific computer to be able to access the desired product regardless of the user. This could be thought of like using a public library computer with a connection to a database, it doesn’t matter what library patron is using the computer they have access to that data only when on the libraries computer.
  • Processor License – A Processor License includes access for an unlimited number of users to connect from either inside the local area network (LAN) or wide area network (WAN) or outside the firewall. You do not need to purchase additional server licenses, CALs, or Internet Connector Licenses when you acquire Processor Licenses. If utilizing Processor licenses, one processor license must be purchased for each physical processor.

Doesn’t seem overly complicated right? Microsoft has several pages answering questions and giving examples of instances when a certain type of license is needed. Microsoft has even set up a page answering these questions because they come up so often with users, it can be found here. Some of the questions include:

  • Does my Multi-function Printer need a CAL? Do my servers need a CAL?
  • Do my external users need a CAL?
  • Do I need a CAL when my Windows Server is used to run a web server?
  • Can I use my CALs to access someone else’s server?


Understanding the types of licenses is only part of the struggle, another part is knowing the volume of licenses that you need to operate. Being under licensed can lead to costly SAM audits. This is where Microsoft audits users operating on their software and attempts to verify that the correct number of licenses have been purchased. If someone is found out of compliance Microsoft will require them to purchase the additional license and they may be subject to other penalties. My Choice Software has created a tool to help customers calculate how many CALs they need in order to stay compliant with their CAL-culator.

It is also important to note that CALs are version and functionally specific, meaning that you need to match a SQL 2014 CAL to a SQL 2014 server. Later versions may also work but not earlier ones, and Open License CALs can be purchased with downgrade rights. Downgrade rights means that the purchase of a recent version also includes the download and use of previous versions of the product. Read more about Open License Products here.

Exchnage CAL Sharepoint CAL Windows Server CAL SQL User CAL 2012 SQL Device CAL 2016

Understanding how Client Access Licensing works is important both functionally and financially. Being under or over licensed can have unforeseen immediate and future costs associated with them so it is important to understand what products fulfill your organization’s needs. Using tools like CAL-culators or even making a call to authorized sellers of CALs and software is well worth the time and effort when navigating licensing.

2 responses to “CAL-culating Client Access Licensing

  1. One thing not clearly outlined here (although it may be implicit with the images of SharePoint, Windows Server, SQL Server, Exchange Server) is whether this impacts the office suite (PP, Word, Excel) and Visio.

    Also not clear is whether there is any attempt to try to apply CALs retroactively to existing product suites (prior versions of the office suites that are provided with license keys).

    It would be useful to deal with those questions – even if just to say they remain unaffected – in this article.

    1. Good thoughts and questions. CALs almost exclusively refer to server connection and communication. So specific applications from Microsoft Office like Word or Excel do not require a CAL for access. The slight exception to this would be a Remote Desktop Server that hosts those applications. In order to ensure that all users accessing the Office Applications are licensed to do so they require CALs to be purchased for each user that accesses the server with the Applications on them.

      As far as applying CALs retroactively, CALs can be purchased at anytime that a new user needs access to a server or in order to become compliant for users that were accessing servers illegally. The versions of the products and CALs must match i.e. a 2012 RDS server needs a 2012 RDS CAL, a 2008 RDS CAL would not work. Open License CALs however do have downgrade rights that would allow newer versions of CALs to access older versions of servers.

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