Checking old product keys (Office 2016 Prof Plus) / Presumably linked to an old Microsoft account

Question

Checking old product keys (Office 2016 Prof Plus) / Presumably linked to an old Microsoft account

Simon August 0

I have three older product keys (from 2017–2020) for Microsoft Office Pro Plus 2016. They were likely linked to an old Windows account of mine. I still have the relevant emails, but I believe the accounts have already been closed. The keys should technically still be valid. Question 1: How can I check which account the product keys were linked to? Question 2: How can I reactivate them?

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2 answers

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Answer 1

Henry-N 15,890 Microsoft External Staff Moderator

Hi @Simon August,

Thank you for posting your question in the Microsoft Q&A forum.

Regarding that you are having issue about Office pro plus 2016. I’d like to ask a quick questions to better understand your situation and assist you effectively:

Could you please reconfirm where did you bought the office pro plus 2016 from?

Microsoft Office 2016 Professional Plus (LTSC) is primarily offered for use in companies or corporations and in most cases activated with a MAK (Multiple Activation Key) or KMS (Key Management Service). These licensing models are designed for organizations and allow activation on a specific number of devices (MAK) or by an enterprise KMS server.

And if you purchased the license through a reseller, please contact them to verify the legitimacy of the product key and possibly exchange or refund. They are the only people who can confirm whether the key has been used before or provide you with a valid one.

Thank you for your understanding.

If you have any additional questions or need further guidance, please let me know.

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Simon August 0 Reputation points

2026-06-10T15:20:01.8233333+00:00

Hi Henry, thanks for your answer. I got the key from the "rakuten.de" website.

The situation is that I have already used the product key. Since my laptop broke down and I bought a new one, I need to handle the re-installation. In the meantime, I used freeware, but I have now found the product keys again. Now I would like to check, how I can use my product keys to use office.
Henry-N 15,890 Reputation points Microsoft External Staff Moderator

2026-06-12T12:47:34.55+00:00

Hi @Simon August,

Thank you for your response.

As you mentioned that the product key was purchased from a reseller, I recommend contacting the reseller directly to receive detailed guidance on how to reuse or reinstall the product. They are in the best position to verify the status of the key (for example, whether it is still valid or already tied to a previous activation) and to advise on any reactivation steps or provide support if needed.

For volume license products such as Office Professional Plus 2016, activation is typically managed through organizational licensing methods (MAK or KMS), and these keys are generally not associated with personal Microsoft accounts. Because of this, reinstallation and reuse depend heavily on how the key was originally issued and activated.

Thank you for your understanding.

Answer 2

For current Office products, most tasks no longer use the product key directly; instead, the product is tied to a Microsoft account. The context provided does not describe any supported way to:

Look up which Microsoft account a specific Office 2016 Professional Plus key was originally associated with, or
Reactivate or reassign those specific keys when the original Microsoft accounts have been closed.

The available guidance focuses on:

Using a Microsoft account (rather than a product key) to install and activate Office once a key has already been redeemed.
General help for finding product keys and getting support if a key is lost or damaged but with valid proof of purchase.

Given that, the only supported path in the context for issues with older keys is to contact Microsoft Support with proof of purchase and request assistance or replacement options.

Practical steps based on the context:

Go to the Microsoft support contact page: https://support.microsoft.com/contactus
Enter a topic such as “Billing” or “Office product key” and press Enter.
Select “Contact support.”
Choose the appropriate product and category (for example, Office / Subscription & billing or similar).
Provide the product keys and any proof of purchase (emails, receipts) so an agent can check the keys and advise whether they can be reactivated, replaced, or otherwise used.

If the keys were volume licenses (for example, from an organization), the organization’s Volume Licensing administrator or Volume Licensing Support would need to be involved, as those keys are managed differently and are not tied to personal Microsoft accounts.

References: