Office 2021 LTSC vs Professional Plus: The Real Differences

Office LTSC Professional Plus 2021 and “retail” Office Professional Plus 2021 contain the same applications, but they are not the same product. Office 2021 LTSC is the volume-licensed version: it activates with a MAK key or a KMS server, is deployed with the Office Deployment Tool and stays frozen on its original version, without a few collaborative features such as real-time co-authoring. The retail version activates with an individual licence key tied to one PC and follows the consumer update channel.

For a home user or a freelancer, the retail version is the simplest. For an organisation equipping several identical computers, LTSC with a MAK key saves a great deal of time. Here are the practical differences, as we come across them every week at support.

What is Office LTSC 2021?

LTSC stands for Long Term Servicing Channel. Microsoft launched Office LTSC 2021 on 16 September 2021 for volume licensing customers, a few weeks before the consumer version of Office 2021 (5 October 2021). It was designed for environments that must not change: production workstations, machines connected to industrial controllers, public bodies, or any fleet where you want an identical interface for years.

According to the official Office LTSC 2021 overview on Microsoft Learn, the Professional Plus edition includes Word, Excel, PowerPoint, Outlook, OneNote, Access, Publisher and Skype for Business. It installs via Click-to-Run, like the retail version, and receives no new features after release: only security and stability fixes, usually published on the second Tuesday of the month.

What are the licensing and activation differences?

This is the fundamental difference. The table below summarises what distinguishes the two versions in terms of licensing, installation and maintenance.

An important point to remember: a MAK key only activates a volume installation, and a retail key only a retail installation. In our experience, this is the number one cause of “This product key didn't work” messages: the customer downloaded the wrong variant. If you already have a retail installation and a MAK key, you need to uninstall Office and then reinstall the volume version with the Office Deployment Tool.

Which features are missing from Office LTSC 2021?

Microsoft states it on its What's new in Office 2021 page: some new features in the retail version are not available in Office LTSC 2021. On Windows, these are:

• Co-authoring: several people cannot edit the same document in real time.
• Modern comments (threaded discussions, @mentions) and seeing who else is in the document.
• The visual refresh: LTSC keeps the older interface style (Office 2019 ribbon and icons).
• Sheet views in Excel, which let everyone filter a shared workbook without disrupting others.
• The Accessibility ribbon in Excel and link to a slide in PowerPoint.

Everything else is shared: XLOOKUP, dynamic arrays, the LET function, dark mode in Word, translation in Outlook, the Draw tab, and support for the OpenDocument 1.3 format. For typical individual use (letters, spreadsheets, presentations), these gaps go unnoticed. They mainly matter if your team works together on the same files stored in OneDrive or SharePoint.

How is Office LTSC 2021 deployed?

The LTSC version cannot be downloaded from a personal Microsoft account. You use the Office Deployment Tool (ODT), a small free Microsoft utility that reads a configuration.xml file. Here is the procedure we follow for a computer in English:

1. Download the Office Deployment Tool from the Microsoft Download Center and extract it to a folder, for example C:\ODT.
2. Create a configuration.xml file containing, at minimum, <Add OfficeClientEdition="64" Channel="PerpetualVL2021">, a <Product ID="ProPlus2021Volume" PIDKEY="your MAK key"> element and the language <Language ID="en-gb" /> (or en-us).
3. Open Command Prompt as administrator, go to the folder and run setup.exe /configure configuration.xml.
4. To prepare several computers without downloading again each time, first run setup.exe /download configuration.xml with a SourcePath pointing to a shared folder.
5. Open Word, go to File > Account and check that it says “Product Activated”.

Microsoft provides a complete example in its Deploy Office LTSC 2021 documentation. The same principle lets you exclude applications (for example Access or Skype for Business) with the ExcludeApp tag. If you are looking for an offline installation image instead, or are unsure between 32-bit and 64-bit, see our article on downloading Office 2021 Pro Plus.

The retail version, on the other hand, installs with the standard Click-to-Run program: you run the installer, enter the key, and activation happens online.

How do you check and activate a MAK key from the command line?

Across a fleet, it is quicker to use the ospp.vbs script than the interface. Open Command Prompt as administrator and go to C:\Program Files\Microsoft Office\Office16 (the Program Files (x86) folder for a 32-bit installation on 64-bit Windows):

• cscript ospp.vbs /inpkey:XXXXX-XXXXX-XXXXX-XXXXX-XXXXX installs the MAK key;
• cscript ospp.vbs /act starts activation (an internet connection is required for a MAK key);
• cscript ospp.vbs /dstatus shows the licence status, the channel (retail or volume) and the last five characters of the key.

If /dstatus returns “LICENSE STATUS: ---LICENSED---”, the computer is properly licensed. If several licences appear, especially after migrating from an older version, remove the old one with cscript ospp.vbs /unpkey: followed by the relevant last five characters.

A quick reminder: KMS “activators” downloaded from forums have nothing to do with a real organisational KMS server. They modify the system, are regularly detected as malware and grant no right of use. A legitimate MAK key remains the only clean solution outside a corporate infrastructure.

Office 2021 LTSC or retail: which should you choose?

Our recommendation depends mainly on the number of computers and how you work:

• A single PC, personal or freelance use: the retail version. Five-minute installation, all Office 2021 features, no XML to edit. This is the case for Office 2021 Professional Plus for 1 PC.
• Several identical computers in a business, school or charity: the volume licence. One key, one configuration file, a repeatable installation. That is the benefit of Office 2021 Pro Plus with a MAK licence.
• A team co-authoring documents on OneDrive or SharePoint: go for retail, or a more recent version, as co-authoring does not exist in LTSC 2021.

If you are still unsure between the consumer editions (Home & Student, Home & Business, Pro Plus), our comparison of the differences between the Office 2021 editions covers it all.

What about after 13 October 2026?

Office LTSC 2021 and retail Office 2021 reached end of support on the same day, 13 October 2026. Both versions continue to work normally: activation stays valid, applications open, files are intact. Microsoft simply no longer publishes fixes. There is no paid extended support for LTSC 2021.

For a new deployment, Office 2024 takes over with the same logic (an LTSC 2024 version for volume, a 2024 version for home users and small businesses) and support until October 2029. On an individual PC, Office 2024 Pro Plus for Windows is the forward-looking option.

Frequently asked questions

Can you convert retail Office 2021 to LTSC without reinstalling?

No. The two versions use different product IDs. You need to uninstall the retail version, restart, and then install ProPlus2021Volume with the Office Deployment Tool and the MAK key.

How can I tell whether my Office 2021 is LTSC or retail?

In File > Account, LTSC shows “Office LTSC Professional Plus 2021” and version 2108. You can also run cscript ospp.vbs /dstatus: the licence description shows the retail or volume channel.

Does a MAK key work without the internet?

MAK activation happens online. On a computer without internet access, Microsoft's offline activation option displays a link or QR code to open on a smartphone to obtain the confirmation ID. Once activated, Office works offline.

Is Office LTSC 2021 available for Mac?

Only Office LTSC Standard for Mac 2021 exists, without Access or Publisher. Professional Plus is for Windows 10 and Windows 11 only.

Does LTSC 2021 include Teams?

Microsoft states that the Teams client is no longer included in new installations of Office LTSC 2021; existing installations are not affected, and Teams can be installed separately if needed.

Equip your computers with the right licence

Retail for a single computer, LTSC with a MAK key for a uniform fleet: the choice comes down mainly to the number of machines and whether you need co-authoring. If you are unsure which variant to install or get an error message at activation, our support team can help you check your configuration before and after purchase. And to follow what the end of support changes, our guide to the end of support for Office 2021 sets it all out.