Product Key Issues

How to Fix Office 2016 Product Key Already Used Error

Elise Williams Oct 9, 2026 870 views

Question details

The user needs to redeem or install Office 2016 but is unable to proceed because the system states the product key has already been used.

How to Fix Office 2016 Product Key Already Used Error

Product: Microsoft Office 2016
Device & OS: not provided
Scenario: Attempting to redeem, install, or activate an Office 2016 product key.
Observed behavior: The system returns a TokenAlreadyRedeemedByOtherMSA error, indicating the 25-character product key is already linked to another Microsoft account.

Before you start

Before troubleshooting, gather any email addresses, phone numbers, or Skype IDs you might have used previously, as you will likely need them to identify the original Microsoft account associated with the license.

Solution 1Recommended

Sign in with the Original Microsoft Account

The most common and direct fix is to log into the exact Microsoft account that was used during the initial redemption of the product key.

Retail Office 2016 product keys are permanently bound to a Microsoft account upon first use. Once bound, the key itself can no longer be used for activation. Instead, the account acts as your digital license.

Navigate to the Microsoft portal

Open your web browser and go to the official Microsoft Services and subscriptions page (account.microsoft.com/services).

Sign in with your account

Locate your Office 2016 license

Scroll through the 'Services & subscriptions' section to find your Office 2016 product listing.

Install and activate

Click the 'Install' button next to the Office 2016 listing to download the installer. Signing into the installed applications with this account will automatically activate the software.

Sign in with the Original Microsoft Account

Activation Tip: If you have multiple Microsoft accounts, try checking each one if you don't immediately see the Office 2016 license listed.

Solution 2

Use the Microsoft Account Recovery Tool

If you forgot the email or password associated with your Office 2016 license, you must use the recovery process to regain access.

Solution 3

Contact Microsoft Support

If the key was redeemed by someone else or you cannot recover the account through automated tools, official support is required.

Free Microsoft Office alternative

Switch to WPS Office to Avoid Activation Hassles

Tired of dealing with product key errors, account lockouts, and complicated activation processes? WPS Office offers a free, lightweight, and highly compatible alternative to Microsoft Office. Enjoy familiar tools instantly without worrying about single-use licenses.

1. Download the installer: Visit the official WPS website and click the free download button.
2. Install WPS Office: Run the downloaded installer and follow the quick setup instructions.
3. Open your files: Instantly open and edit your existing Microsoft Office documents without needing a product key.

Free to use with no complex product key or activation requirementsFully compatible with Microsoft Word, Excel, and PowerPoint formatsLightweight installation that runs smoothly on Windows, Mac, and LinuxFamiliar user interface for a seamless migration from Microsoft Office

Frequently Asked Questions

Can I reuse my Office 2016 product key on a new computer?

No, the 25-character product key can only be redeemed once. To install Office on a new computer, you must sign in to your Microsoft account on the new device and download the software from the Services and subscriptions page.

Why does my newly purchased product key say it's already been used?

If you purchased the product key from an unauthorized third-party seller, they may have sold you a duplicated or previously redeemed key. You will need to contact the seller for a refund or a replacement key.

How do I find which Microsoft account is linked to my Office 2016 key?

For privacy reasons, Microsoft does not display the full email address linked to a product key. You will need to test signing in with all your known email addresses at Office.com to see which account contains the active subscription.

Can I transfer my Office 2016 license to a different Microsoft account?

Generally, retail Office 2016 licenses cannot be transferred between Microsoft accounts once they are linked. The license is permanently bound to the original account used during redemption.

Installation & Activation