In
software licensing
A software license is a legal instrument governing the use or redistribution of software.
Since the 1970s, software copyright has been recognized in the United States. Despite the copyright being recognized, most companies prefer to sell lic ...
, volume licensing is the practice of using one license to authorize software on a large number of computers and/or for a large number of users. Customers of such licensing schemes are typically
business
Business is the practice of making one's living or making money by producing or Trade, buying and selling Product (business), products (such as goods and Service (economics), services). It is also "any activity or enterprise entered into for ...
, governmental or educational institutions, with prices for volume licensing varying depending on the type, quantity and applicable subscription-term. For example,
Microsoft
Microsoft Corporation is an American multinational corporation and technology company, technology conglomerate headquartered in Redmond, Washington. Founded in 1975, the company became influential in the History of personal computers#The ear ...
software available through volume-licensing programs includes
Microsoft Windows
Windows is a Product lining, product line of Proprietary software, proprietary graphical user interface, graphical operating systems developed and marketed by Microsoft. It is grouped into families and subfamilies that cater to particular sec ...
and
Microsoft Office
Microsoft Office, MS Office, or simply Office, is an office suite and family of client software, server software, and services developed by Microsoft. The first version of the Office suite, announced by Bill Gates on August 1, 1988, at CO ...
.
Traditionally, a volume licensing key (VLK), which could be supplied to all instances of the licensed computer program, was involved in volume licensing. With the popularity of the
software as a service
Software as a service (SaaS ) is a cloud computing service model where the provider offers use of application software to a client and manages all needed physical and software resources. SaaS is usually accessed via a web application. Unlike o ...
practices, volume licensing customers only supply their software with credentials belonging to an online
user account
A user is a person who uses a computer or network service.
A user often has a user account and is identified to the system by a username (or user name).
Some software products provide services to other systems and have no direct end use ...
instead, which is used for other aspects of services and provisioning.
Overview
Traditionally, a
product key
A product key, also known as a software key, serial key or activation key, is a specific software-based key for a computer program. It certifies that the copy of the program is original.
Product keys consist of a series of numbers and/or letters ...
has been supplied with computer programs. It acts analogously to a
password
A password, sometimes called a passcode, is secret data, typically a string of characters, usually used to confirm a user's identity. Traditionally, passwords were expected to be memorized, but the large number of password-protected services t ...
: The computer programs of old ask the user to prove their entitlement; in response, the user provides this key. This key, however, must only be used once, i.e. on one computer. A volume licensing key (VLK), however, can be used on several computers. Vendors can take additional steps to ensure that their products' key are only used in the intended number. These efforts are called
product activation
Product activation is a license validation procedure required by some proprietary software programs. Product activation prevents unlimited free use of copied or replicated software. Unactivated software refuses to fully function until it ''determi ...
.
Volume licenses are not always transferable. For example, only some types of Microsoft volume license can be transferred, provided a formal transfer process is completed, which enables Microsoft to register the new owner. A very small number of software vendors specialize in brokering such transfers in order to allow the selling of volume licenses and keys. The most notable of these,
Discount-Licensing, pioneered the sale of Microsoft volume licenses in this way.
Notable examples
Microsoft

Microsoft has been engaged in volume licensing since its inception, as the enterprise sector is its primary market. With the release of
Windows XP
Windows XP is a major release of Microsoft's Windows NT operating system. It was released to manufacturing on August 24, 2001, and later to retail on October 25, 2001. It is a direct successor to Windows 2000 for high-end and business users a ...
in 2001, Microsoft introduced
Microsoft Product Activation
Microsoft Product Activation is a DRM technology used by Microsoft in several of its computer software programs, most notably its Windows operating system and its Office productivity suite. The procedure enforces compliance with the program's ...
, a
digital rights management
Digital rights management (DRM) is the management of legal access to digital content. Various tools or technological protection measures, such as access control technologies, can restrict the use of proprietary hardware and copyrighted works. DRM ...
(DRM) scheme to curb
software piracy
Online piracy or software piracy is the practice of downloading and distributing copyrighted works digitally without permission, such as music, movies or software.
History
Nathan Fisk traces the origins of modern online piracy back to similar ...
among consumers by verifying the user's entitlement to the product license. At the time, however, the volume-licensed versions of Windows XP were exempt from this measure. (See .) Starting with
Windows Vista
Windows Vista is a major release of the Windows NT operating system developed by Microsoft. It was the direct successor to Windows XP, released five years earlier, which was then the longest time span between successive releases of Microsoft W ...
, Microsoft introduced two volume licensing methods for IT professionals in charge of installing Windows in organizations, both of which are covered by Microsoft Product Activation: The first is Multiple Activation Keys (MAK), which are the same as Windows XP's volume licensing keys but require product activation. The second is
Key Management
Key management refers to management of Key (cryptography), cryptographic keys in a cryptosystem. This includes dealing with the generation, exchange, storage, use, crypto-shredding (destruction) and replacement of keys. It includes cryptographic ...
Server (
KMS) and its corresponding keys. Hosts activated via a KMS have to report back to a
software license server once every 180 days. Licenses using these schemes can be procured via the
Microsoft Software Assurance
Microsoft Software Assurance (SA) is a Microsoft maintenance program aimed at business users who use Microsoft Windows, Microsoft Office, and other server and . The core premise behind SA is to give users the ability to spread payments over seve ...
program.
A large group of Microsoft customers are OEMs that assemble and sell computers, such as desktops, laptops, tablet computers and mobile device. In the devices sold by these OEMs, Windows license data is stored in the computer's BIOS in an area referred to as the "ACPI_SLIC", so that KMS can detect the use of previous Microsoft products even with the storage device removed or erased. For Windows Vista and
Windows 7
Windows 7 is a major release of the Windows NT operating system developed by Microsoft. It was Software release life cycle#Release to manufacturing (RTM), released to manufacturing on July 22, 2009, and became generally available on October 22, ...
, the SLIC data are complementary; a volume licensing product key is still supplied with the device, which the user needs in the event of reinstalling Windows. Starting with
Windows 8
Windows 8 is a major release of the Windows NT operating system developed by Microsoft. It was Software release life cycle#Release to manufacturing (RTM), released to manufacturing on August 1, 2012, made available for download via Microsoft ...
, however, everything needed to authorize the device is stored with SLIC data.
In 2010, Microsoft introduced the
Office 365
Microsoft 365 (previously called Office 365) is a product family of productivity software, collaboration and cloud-based services owned by Microsoft. It encompasses online services such as Outlook.com, OneDrive, Microsoft Teams, programs form ...
licensing program. in which
Microsoft Office
Microsoft Office, MS Office, or simply Office, is an office suite and family of client software, server software, and services developed by Microsoft. The first version of the Office suite, announced by Bill Gates on August 1, 1988, at CO ...
,
Microsoft Exchange Server
Microsoft Exchange Server is a mail server and calendaring server developed by Microsoft. It runs exclusively on Windows Server operating systems.
The first version was called Exchange Server 4.0, to position it as the successor to the relat ...
and
Skype for Business Server products are licensed based on the
software as a service
Software as a service (SaaS ) is a cloud computing service model where the provider offers use of application software to a client and manages all needed physical and software resources. SaaS is usually accessed via a web application. Unlike o ...
(SaaS) model: In exchange for a monthly subscription fee, software, its updates, support for them, provisioning, administration, licensing and additional services are all provided through an online web-based dashboard. In this scheme, licensed apps communicate recurrently with Microsoft over the Internet; as such, a product key needs not be issued to the user. Instead the administrator needs to sign up for
Microsoft account
A Microsoft account or MSA (previously known as Microsoft Passport, .NET Passport, and Windows Live ID) is a single sign-on personal user (computing), user account for Microsoft customers to Login, log in to consumer Microsoft services (like Ou ...
, which holds details such as licensed apps, their number, and payment methods. This account is protected by credentials such as a username and a password.
Adobe
Introduced in 2011,
Adobe Creative Cloud
Adobe Creative Cloud is a set of applications and services from Adobe Inc., Adobe that gives subscribers access to a collection of software used for graphic design, video editing, web development, photography, along with a set of mobile applicat ...
is a SaaS offering in which software produced by
Adobe
Adobe (from arabic: الطوب Attub ; ) is a building material made from earth and organic materials. is Spanish for mudbrick. In some English-speaking regions of Spanish heritage, such as the Southwestern United States, the term is use ...
, their updates, support for them, provisioning, administration, licensing and additional services are all provided over the Internet, in exchange for a monthly subscription fee. As with the Office 365, a user account registered with Adobe is all that is required to authorize software and store payment information.
Unauthorized use
Microsoft has blocked several volume license keys that have been abused in service packs, starting with Windows XP Service Pack 1. Microsoft even developed a new key verification engine for Windows XP Service Pack 2 that could detect illicit keys, even those that had never been used before. Several
security
Security is protection from, or resilience against, potential harm (or other unwanted coercion). Beneficiaries (technically referents) of security may be persons and social groups, objects and institutions, ecosystems, or any other entity or ...
consultants have condemned the move by Microsoft, saying that leaving a large install base unpatched from various security holes is irresponsible because this unpatched install base can be leveraged in large scale Internet attacks, such as
Trojan horses used to send
spam e-mail. Others have come to Microsoft's defense, arguing that Microsoft should not have to provide support for illegal users. After much public outcry, Microsoft elected to disable the new key verification engine. Service Pack 2 only checks for the same small list of commonly used keys as Service Pack 1. Users of existing installations of Windows XP can also change their product key by following instructions from Microsoft.
Leaked keys
A volume license key that was commonly used to bypass
product activation
Product activation is a license validation procedure required by some proprietary software programs. Product activation prevents unlimited free use of copied or replicated software. Unactivated software refuses to fully function until it ''determi ...
in early versions of Windows XP was
FCKGW-RHQQ2-YXRKT-8TG6W-2B7Q8
. This key was part of the first
warez
Warez refers to pirated software and other copyrighted digital media—such as video games, movies, music, and e-books—illegally distributed online, often after bypassing digital rights management (DRM). The term, derived from “software wa ...
release of the final version of Windows XP by a group called ''devils0wn'', 35 days before the operating system's official retail release on 28 August 2001. The key is now obsolete, as it has been blacklisted by Microsoft since August 2004, and affected computers will display a
WGA notification. It was made famous partly because it featured in a popular image circulated on the Internet before the retail launch of Windows XP. In the image, the key is written on a CD-R containing the leaked operating system and held in front of a digital Microsoft sign counting down the days until the release of Windows XP.
Users using these keys will receive an error message when they install the latest
service pack
In computing, a service pack comprises a collection of updates, fixes, or enhancements to a software program delivered in the form of a single installable package. Companies often release a service pack when the number of individual patches to a ...
, and such users are told to obtain a legitimate license and change their product key.
Publicly accessible Key Management Servers
Any client machine with the correct Key Management Server (KMS) client setup keys can authenticate against any KMS server. KMS client keys are well known and documented publicly by Microsoft. KMS servers require a minimum of 25 clients to properly activate, but also stop counting additional licenses beyond 50, and automatically accept any client key once reaching the 25 client threshold.
Businesses operating KMS servers are required to properly shield the KMS server behind firewalls so that it cannot be reached from the Internet and be used by the general public to authorize illegitimate KMS client keys. Public exposure of a KMS server can result in Microsoft revoking the server key, thereby disabling all attached clients.
External KMS server access is desirable for devices on long-term leave away from the corporate network, as KMS client activation will expire after six months of not being able to contact a KMS server. For this situation, a business can make it accessible through a
virtual private network
Virtual private network (VPN) is a network architecture for virtually extending a private network (i.e. any computer network which is not the public Internet) across one or multiple other networks which are either untrusted (as they are not con ...
(VPN) known only to the devices outside the corporate network.
KMS server and client emulators
An unofficial KMS server emulator exists that will activate Windows or Office even if the software was not licensed or paid for, regardless of whether or not there are 25 or more computers on the network, and regardless of whether or not a previous version of Windows was installed. There is also a program that will send KMS requests to a legitimate KMS server, in order to fool the server into thinking that there are 25 or more computers on the network. Microsoft considers both of these exploits to be a violation of the Terms and Conditions.
References
{{Reflist
Microsoft software
Software licensing
Windows Vista
Windows XP