icon1 Year Warranty on Refurbished Laptops iconFree UK Delivery iconGrade A Laptops (Certified Refurbished)

  • Your shopping cart is empty!

How to Activate Microsoft Office (2019, 2021 & 2024)

This guide explains how to install and activate Microsoft Office using a product key. If you purchased an Office key from us, you’ll receive the key by email after checkout. Follow the steps below and use the common fixes if you hit an error.

View all activation guides (Windows, Office & ESET)
Jump to: Install & activation steps | Common issues | Buy Office keys
Need an Office key?

If you haven’t purchased yet, you can browse Office keys below. Digital delivery by email with clear activation steps.

Browse all Office keys Back to all guides

Top Office keys

Tip: If you’re unsure which version you need, check the “Which Office should I choose?” section below or contact us.

Before you start

  • Make sure your PC is connected to the internet.
  • Close all Office apps (Word, Excel, Outlook etc.) before activating.
  • Have your product key ready (usually 25 characters: XXXXX-XXXXX-XXXXX-XXXXX-XXXXX).
Tip: Activation steps can vary slightly depending on the exact Office edition you purchased (e.g. Office 2019 / 2021 / 2024, or a Microsoft 365 subscription). If your screen looks a little different, continue with the closest matching option below.

Step 1: Install Microsoft Office

If Office is already installed on your PC, you can skip to Step 2.

Option A: Install from your Microsoft account (recommended)

  1. Sign in to your Microsoft account in your web browser.
  2. Go to the Office install area shown in your account (it may be listed under Services & subscriptions).
  3. Download and run the installer.
  4. Once installed, open Word or Excel.

Option B: Install from the official Office setup prompt

  1. If your email includes an install link/instructions, open the link and download the installer.
  2. Run the installer and complete setup.
  3. Open Word or Excel once finished.

Step 2: Activate Office using your product key

Method A: Activate when prompted (most common)

  1. Open Word (or any Office app).
  2. If you see an activation screen, choose Enter a product key.
  3. Type/paste your key and follow the on-screen steps.
  4. Restart the Office app after activation completes.

Method B: Enter the key from inside an Office app

  1. Open Word or Excel.
  2. Go to File → Account (or Office Account).
  3. Look for Change Product Key or Activate Product.
  4. Enter your key and complete activation.
Important: If you have multiple Office versions installed (or a Microsoft 365 trial), activation can conflict. If activation fails, see the “Common issues” section below.

Common activation issues (and quick fixes)

1) “This product key has already been used” / “The key isn’t valid”

  • Double-check for typing mistakes (common: B vs 8, O vs 0).
  • Make sure you’re activating the correct version/edition (2019 vs 2021 vs 2024).
  • Restart the PC and try again (it sounds simple, but it often resolves activation prompts).

2) Office keeps asking you to “Sign in” instead of accepting a key

  • This can happen if a Microsoft 365 trial or pre-installed Office version is taking priority.
  • Go to Control Panel → Programs and Features and check what Office versions are installed.
  • If you have old/trial versions, uninstall them, restart, then reinstall/activate the version you purchased.

3) You see “Unlicensed Product” in Word/Excel

  • Open Word → File → Account and check activation status.
  • Click Sign out (if signed into the wrong Microsoft account), close Office, reopen and try activation again.
  • Make sure Windows date/time are correct (incorrect time can break activation).

4) Activation error codes or “Something went wrong”

Most errors are quick fixes once we see the exact message. Take a screenshot of the error and include your order number when contacting us.

Microsoft Office Activation FAQ

Do I need a Microsoft account to activate Office?

It depends on the edition and the activation screen you see. Some versions activate by entering a product key directly, while others may prompt you to sign in. If you’re asked to sign in, use the Microsoft account you want the licence associated with and follow the on-screen steps.

Office keeps asking me to sign in instead of accepting my key — what should I do?

This is often caused by a pre-installed Office trial or Microsoft 365 version taking priority. Check Control Panel → Programs and Features for older/trial Office installs, uninstall them, restart, then reinstall/activate the edition you purchased.

Can I reinstall Office later?

Usually yes, especially when reinstalling on the same PC. If you reinstall and activation prompts appear again, follow the same activation steps. If you get an error message, send us a screenshot and your order number and we’ll help you resolve it.

Why does Office show “Unlicensed Product” after I entered the key?

Close all Office apps, restart your PC, then open Word/Excel and check File → Account. Also ensure your Windows date/time is correct. If it still shows unlicensed, there may be a conflicting Office installation or activation didn’t complete.

Support tip: If you contact us, include your order number and a screenshot of the activation screen/error to help us resolve it faster.

Still need a Office key?

Browse Office Keys Contact Support

Related guides