Why an Office 2021 Key Cannot Upgrade Office 2016 ProPlus

Office product keys are version-specific. An Office 2016 Professional Plus key cannot be used to install or activate Office 2021 Pro Plus.

The direct answer

Your 2016 key stays tied to Office 2016

Microsoft perpetual Office licenses do not convert forward to a newer perpetual release. The key you already own remains valid for the version it was issued for.

What this means in practice

• You can reinstall Office 2016 with your existing Office 2016 Professional Plus key.
• You cannot use that same key to gain access to Office 2019 or Office 2021.
• If you want Office 2021 Pro Plus, you need a license for Office 2021 Pro Plus.

Can reinstalling unlock a newer version?

No. Removing Office 2016 does not change the license attached to your product key.

Removing Office 2016 only deletes the installed apps from your PC. It does not upgrade the license.

Running Office setup again restores the edition and version that your existing key is entitled to use.

An Office 2016 Professional Plus key still activates Office 2016, not Office 2019 and not Office 2021.

What happens with each choice

How Office version licensing works

The source guidance is clear: there is no direct upgrade path where an older perpetual Office key becomes valid for a newer perpetual release.

Perpetual keys are version-bound

A key issued for Office 2016 Professional Plus is meant for that release, not later standalone editions.

No automatic upgrade entitlement

Installing a newer Office package does not create rights your original license never included.

Install and activation are separate

You may be able to run setup, but activation still depends on owning the correct version license.

What you need for Office 2021 Pro Plus

If you want the newer version, you must purchase the version or license type you actually plan to use.

• Buy a valid license for Office 2021 Pro Plus if that is the edition you want.
• Install the newly licensed version after purchase.
• Remove Office 2016 afterward if you do not want to keep the older installation.

Verification before you replace anything

Check the license you own first. If the only key you have is for Office 2016 Professional Plus, the expected result is continued access to Office 2016 only.

A successful move to Office 2021 requires a separate Office 2021 entitlement. Without that, setup does not become an upgrade mechanism.

A timing note before you buy

One source reply noted that Office 2024 was expected later in the year, so waiting could be worth considering before purchasing another perpetual version.

Buy now if you need the newer version immediately

If Office 2021 Pro Plus is required right away, the practical path is still to purchase that version specifically.

Wait if release timing matters more

If you are not in a rush, it may make sense to compare your options closer to the next perpetual release window.

Office 2016 keys do not upgrade forward

If your only license is for Office 2016 Professional Plus, reinstalling restores Office 2016 and nothing newer. To use Office 2021 Pro Plus, you need to purchase that version specifically, and waiting for a later perpetual release may be worth considering if timing is flexible.

Use WPS Office as a Free Microsoft Office Alternative

WPS Office provides the compatible local workspace used in the steps below.

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WPS cannot upgrade Microsoft licenses or unlock Office 2021 from an Office 2016 key, but it can help if you need a practical workspace for local DOCX, XLSX, PPTX, and PDF files while deciding what Microsoft license to buy.

You get a familiar ribbon-style interface, PDF tools, and relevant WPS AI support for drafting, summarizing, and document cleanup. Compatibility is strong for everyday files, though some advanced Microsoft-only features and exact layout behavior may differ.

an Office 2021 Key Cannot Upgrade Office 2016 ProPlus FAQs

Can an Office 2016 Professional Plus key activate Office 2021 Pro Plus?

No. The key is version-specific, so an Office 2016 key activates Office 2016, not Office 2021 Pro Plus.

If I uninstall Office 2016 first, can setup switch me to Office 2019 or 2021?

No. Uninstalling changes the installed apps on the PC, but it does not change the license attached to your Office 2016 product key.

How can I verify what version I am actually entitled to use?

Verify the product key or license you purchased. If the entitlement is only for Office 2016 Professional Plus, the supported result is Office 2016 activation only.

What can I use if I only need to work with Office-style documents while deciding?

WPS cannot change Microsoft licensing, activation, billing, tenants, or Microsoft-only controls. For local DOCX, XLSX, PPTX, and PDF work, WPS Office is a free, lightweight option with a familiar UI, PDF tools, and useful WPS AI features, though exact Microsoft-only behaviors and advanced formatting can still vary.