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Fix Microsoft Office 2021 Activation Issue on Second Computer
Question details
The user is unable to activate Microsoft Office Professional Plus 2021 on a second device (such as a laptop or tablet), receiving an invalid product key error.
- Product
- Microsoft Office Professional Plus 2021
- Device & OS
- not provided
- Scenario
- Attempting to install and activate a perpetual Office product key on a secondary device after it was already activated on a primary desktop.
- Observed behavior
- The activation process fails on the secondary device, displaying an invalid product key error message.
Verify the operating system of your second device (Windows, Mac, or Android) and log into your Microsoft Account to check your current license status.
Verify Perpetual License Single-Device Limitations
Office 2021 licenses are designed for a single computer, meaning the same product key cannot activate a second device simultaneously.
A perpetual Office license, such as Office Professional Plus 2021, is strictly intended for use on one computer (either a PC or a Mac). It is not a multi-device subscription.
Understand that Office Professional Plus 2021 is a one-time purchase meant for exactly one device. It cannot be actively shared across your desktop and laptop.
If you need fully featured Microsoft Office on both a desktop and a laptop at the same time, you must purchase a second perpetual license or switch to a Microsoft 365 subscription.
Transfer Your Office License to a New Windows Computer
If your second device is a replacement Windows laptop, you can transfer your activation by logging into your Microsoft account.
Resolve Activation on Android and Tablet Devices
Mobile devices have different licensing requirements and usually cannot be activated with a standard Office 2021 desktop key.
Switch to WPS Office for Multi-Device Productivity
Avoid restrictive single-device licensing limits with WPS Office. Enjoy a free, lightweight, and highly compatible alternative to Microsoft Office that lets you work seamlessly across multiple devices, including Windows, Mac, iOS, and Android using a single account.
- 1. Download WPS Office: Install WPS Office on your desktop, laptop, and mobile devices.
- 2. Sign in to sync: Log in with a single WPS account to automatically sync your documents across all your devices.
- 3. Edit your files: Open your existing Microsoft Office files directly in WPS Office without losing any formatting.
Frequently Asked Questions
Can I use Office Professional Plus 2021 on multiple computers?
No. Office Professional Plus 2021 is a perpetual (one-time purchase) license meant for a single computer. To use Office on multiple devices simultaneously, you need a Microsoft 365 subscription or multiple standalone licenses.
How do I transfer my Office 2021 license to a new computer?
You must first uninstall Microsoft Office 2021 from your old computer. Afterward, install it on your new computer by logging into your Microsoft account at office.com and activating it using your linked account credentials.
Why does my Office product key say invalid on my Android tablet?
Desktop product keys for Office 2021 are not valid for Android or mobile operating systems. To unlock advanced editing features on a tablet, especially ones with screens larger than 10.1 inches, Microsoft requires an active Microsoft 365 subscription.
