After Office 2016/2019: Microsoft 365 or a Perpetual Licence?

October 2025 retired more than Windows 10: Office 2016 and Office 2019 stopped receiving security updates on the same calendar day. Word still opens and Excel still calculates — but an unpatched application that processes documents arriving by email leaves ajar exactly the door attackers love most; office documents are the classic carrier of malware. This article settles the "which Office do we buy" question across the two models.

Two Models, Two Philosophies

Microsoft 365 is a per-user subscription: the Office applications stay permanently current, and the package includes corporate email (Exchange Online), Teams and OneDrive/SharePoint cloud services. A perpetual licence (the Office 2024 family) is a one-time purchase: the version is fixed, no cloud services are included, and security updates run to a set date — after which today's 2016/2019 situation repeats. The real choice is this: does the business want to manage its software as a service, or as an asset?

The Decision Table

Dimension	Microsoft 365	Perpetual (Office 2024)
Payment character	Ongoing per-user subscription	One-off fee per device
Currency	Continuous features + security	Security only; features frozen
Support horizon	As long as the subscription runs	Bound to the version calendar — same decision returns at the end
Corporate email	Included (plan-dependent)	Not included — solved separately
Collaboration (Teams, co-authoring)	Native	Limited
Multiple devices per user	Install rights on several devices	Licence tied to the device
Internet dependency	Needed for setup and validation; work can continue offline	Low

Comparing Costs Honestly

The classic accounting mistake is comparing the perpetual licence's one-off price against a single year of subscription. A sound comparison runs over a 4–5 year window with package contents equalised: on the Microsoft 365 side, email hosting, cloud storage and Teams are inside the fee; on the perpetual side those items are bought separately or ignored. For a business already hosting its email on Microsoft 365, the perpetual licence's "cheapness" is usually optical; for an estate that uses no cloud services and processes documents locally, perpetual can be genuinely economical.

Most Offices' Real Answer: the Mixed Model

User profiles are not uniform, so a single licence type is usually either a gap or a waste. The arrangement we build most often in the field:

• Heavy office users (accounting, sales, management): Microsoft 365 — email, multiple devices and collaboration already make the subscription unavoidable.
• Light-use stations (warehouse terminal, production kiosk, shared shift PC): perpetual licence — pushing a subscription onto a machine that opens and prints documents and has no mailbox is waste.
• View-only seats: free web versions or shared solutions may suffice; not every chair needs the full suite.

The precondition of the mixed model is knowing who actually uses what — the same usage-inventory discipline that governs SaaS subscription management in general.

What Not to Skip in the Transition

• Add-ins and macros: accounting integrations, e-declaration add-ins and years of accumulated Excel macros must be tested on a pilot before the waves; surprises do not belong to production day.
• Legacy file formats: very old archive documents can behave differently on opening; sample-test the critical archive.
• The mixed-version period: while migration proceeds in waves, different versions will touch the same documents; watch shared template compatibility through this window.
• Recording the old licences: which licence remains on which device goes into the inventory — the cost of answering "we don't know" on audit day is well documented.

Yamanlar Bilişim's Contribution to the Licence Decision

Our role in this decision is tailoring, not selling: we profile your users, measure your current email and cloud usage, and put the two models' costs side by side over a 4–5 year window for your specific case. Transition day — add-in tests, data moves, installations — is scheduled outside working hours, and the licence inventory stays current under the maintenance agreement.

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