Moving From Perpetual to Subscription: What You Gain and What You Lose

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A perpetual licence is a thing you hold for one version; a subscription is a service you are inside. The honest comparison is not purchase price against annual price – divide the perpetual figure by the years to its published end of support, then add everything the subscription would have included, and compare the two annual numbers.

1. Date the perpetual side before you price it. Office LTSC 2024, Visio LTSC 2024 and Project 2024 LTSC all reach end of support on 9 October 2029, with five years under the Fixed Lifecycle Policy and no extended phase.
2. Subscribe if headcount moves in either direction. A perpetual licence bought for somebody who leaves is stranded, and reassignment is limited to once per 90 days.
3. Subscribe if you already pay separately for mail, cloud storage, device management and endpoint protection, because a plan that bundles them means you are otherwise buying those things twice.
4. Keep perpetual for machines that must be frozen, isolated or offline. A subscription install needs to reach the internet at least once every 30 days or it enters reduced functionality mode.
5. Do not plan a mixed Office install on one machine. Two Click-to-Run products of different versions with overlapping applications are not supported – though Microsoft 365 Apps alongside Visio LTSC Professional 2024 or Project Standard 2024 is.
6. Price the option to stop. A perpetual licence keeps working through a bad year; a subscription does not, and hosted data is deleted at the end of the lifecycle if it lapses.

Office LTSC has not disappeared. Office LTSC Standard 2024, Office LTSC Professional Plus 2024 and Office LTSC for Mac 2024 are available under desktop application licences through Microsoft Commercial Licensing, and are licensed per device.

If the annualised numbers are close and headcount is stable, staying perpetual is defensible and you can stop here. Below is the arithmetic in full, what the migration actually costs in effort, and the machines that should not move.

Why it happens

A perpetual licence grants indefinite use rights to a specific version. It does not expire, nothing revokes it, and support for it ends on a published lifecycle date rather than a billing one. Once that date passes the software keeps working and stops receiving security updates, which is the point at which a perpetual licence quietly becomes a liability rather than an asset. For the 2024 releases that date is 9 October 2029, and Microsoft is explicit that this is five years under the Fixed Lifecycle Policy with no extended phase behind it.

A subscription grants use rights for as long as you pay, and bundles services with them: mailboxes, cloud storage, collaboration, and in the higher plans device management and security tooling. The applications are the visible part and usually the smaller part of what you are buying. Each licence covers installation on up to five desktops, five tablets and five mobile devices, and past ten devices the one not used for the longest is automatically deactivated.

The behaviour that decides the offline question is published rather than folklore. As long as the computer can connect to the internet at least once every 30 days, Microsoft 365 Apps remain fully functional. Beyond that they enter reduced functionality mode – documents open and print, editing and creating are disabled – until the next connection. That is a specific, checkable threshold rather than a vague warning about needing the internet.

Full reference

Side by side on what actually changes

The arithmetic that settles it

Comparing a one-off purchase with an annual fee is meaningless until both are expressed the same way. Take the perpetual purchase and divide it by the number of years between today and 9 October 2029, which is the published end of support for the 2024 releases. Use that date rather than optimism, because a version you cannot patch is a version you will replace whether you planned to or not.

Then add to that annual figure everything the subscription would have covered and you would otherwise buy: mailboxes and the platform behind them, cloud storage, device management, endpoint protection, mail filtering, and the staff time spent on key management, media and reactivation after rebuilds. Compare the result with the subscription cost multiplied by the seats you will actually assign – assigned, not purchased. The comparison usually looks quite different once the bundled components sit on the same side of the page.

Finally, price the thing that appears on neither invoice: the option to stop. A perpetual licence keeps working through a bad year. A subscription does not, and its hosted data is deleted at the end of the lifecycle – 30 days Expired plus 90 days Disabled for a subscription bought directly. For some organisations that optionality is worth paying for and for others it is irrelevant, but it should be a decision rather than an oversight.

What the migration actually costs in effort

The licence change is the easy part. The work is in mail migration if mailboxes are moving, in identity if accounts are currently local or in an on-premises directory, and in redirecting file locations so documents end up in cloud storage rather than on a departing laptop. Retraining is usually minimal, because the applications are the same applications.

Check add-ins before you commit. Ordinary macros generally survive, but COM add-ins, ageing line-of-business integrations and anything automating an older Office object model deserve testing on one machine before twenty. Old mail archives sitting in local data files also need collecting, because they will not migrate themselves and nobody notices they are gone until somebody needs an email from four years ago.

What can and cannot share a machine

Do not install the subscription apps alongside an existing perpetual suite and plan to tidy up later. Microsoft’s supported-scenarios guidance is that you cannot install two products of different versions if both use Click-to-Run and have overlapping Office applications, and you cannot install two products of the same version using different installation technologies. Record any perpetual keys you may want to reuse, then remove the old suite cleanly before installing the new one.

Visio and Project are the exception worth knowing, because it saves a rebuild. Microsoft lists Microsoft 365 Apps alongside Visio LTSC Professional 2024, and alongside Project Standard 2024, as supported scenarios – the applications do not overlap. A subscription Office estate with a handful of perpetual Visio machines is a normal configuration rather than a compromise, and it is often the cheapest correct answer for a couple of specialists.

Which way to go, by situation

• Headcount moving in either direction: subscribe. Perpetual licences bought for people who then leave are stranded, and reassignment is limited to once per 90 days.
• Small, stable team with no cloud mail and no appetite for it: perpetual is defensible, provided you budget the refresh and diary 9 October 2029.
• Air-gapped, regulated or machine-control PCs: perpetual, specifically Office LTSC, which is built to sit still.
• Already paying separately for mail, storage, device management and antivirus: subscribe, because you are buying those things twice.
• About to buy a 2024 perpetual release late in its life: check the years remaining before you divide. You may be buying a short run at a long-run price.
• Genuinely split requirements: run both, and record in the register which machines are which.

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