Fixing the office activation error ERR_MISSING_PARTNUMBER

When you enter your product key at, you may receive an error message:

“Sorry, we cannot set up your account at this time. Save your product key and try again later. If this happens again, contact support.” (Error code: ERR_MISSING_PARTNUMBER)

The error code ERR_MISSING_PARTNUMBER occurs after entering a valid license key to activate their Office product. This problem occurs after affected users have performed a clean installation or reinstalled the Office package.

This message appears when you enter a product key for an older version of Office that is not available for download from

What causes an Office ERR_MISSING_PARTNUMBER activation error

  • Office for Web Server Failure: This error code may appear due to a common problem with the Office activation server. If this script applies, the problem is completely out of your control. All you can do is find the problem and wait for Microsoft to fix it before you activate your Office package.
  • The incorrect product key or activation service: This can be confusing to many Office users, but not all product keys can be activated through Depending on your Office version, you may need to download and activate them through different links.
  • A user attempts to download a volume license key from to activate: If you are using a volume key for the Office Professional Plus version, you must use either MAK (Multiple Activation Key) or KMS (Key Management Service) to force activation.
  • A user trying to activate a single-purchased license: You may also see this error if you try to activate a license that can only be installed on your computer and is rejected by Microsoft Corporation. In this case, you should contact your Microsoft Live agent and ask them to activate the license remotely.

To eliminate the office activation error ERR_MISSING_PARTNUMBER

Check the status of the Office service.

Before you thoroughly address this problem, you should first make sure that the problem is not widespread and unique to you.

Perhaps the reason you can’t activate your Office package is due to server issues, which are currently being addressed by Microsoft. In these situations, the problem is completely out of your control – all you can do is confirm that the problem is occurring and wait for Microsoft to fix it on their end.

To check for problems that may be affecting Office, visit this website to see if Microsoft is currently reporting any problems with Office (Office for the web -Consumer).

If your investigation reveals no problems with the Office server, you’ve just confirmed that you’re not dealing with a server issue. In that case, use the following methods to take additional steps to resolve the problem if it occurs locally.

Make sure that you have entered the correct product key

If you receive an ERR_MISSING_PARTNUMBER error when you try to register the product at the and you receive one of the following error messages, you should first check the status of the Microsoft Office servers:

  • “Sorry, we cannot set up your account at this time. Please save your product key and try again later. If this happens again, please contact support.”
  • “Sorry, we cannot find this product key in our database.”
  • “Sorry, we can’t create your account at this time.”

Each of these 3 messages will appear in situations where you enter a product key that is actually for an older version of Office – one that is not available for download from /setup.

If this scenario applies to you, you will need to use different links (depending on your version of Office) to activate your Office suite. If you have already used the correct link and have verified that your license key is valid, go to the next method below.

How to use your license key for volume

If you’ve followed the instructions above and you’re still having the same problem, you may be dealing with a volume license key. These are typically used by companies to activate volume versions of Office Professional Plus.

If this scenario applies, you can activate your Volume Edition using a MAK (Multiple Activation Key) or Key Management Service (KMS). Note If you have a system administrator, ask them for help with activation via KMS.

If you do not have a system administrator, follow the instructions below to activate using MAK:

  1. Open your Office (2013, 2016, or 2019) installation, go to File -> Account, and click Change Product Key.
  2. When prompted, enter and submit the MAK key, then follow the on-screen instructions to complete the key entry.
    Note: After entering a valid product key, you will be offered two methods of verification: online activation and phone activation.
  3. Choose the activation method that suits you best, but note that online activation is much faster because you don’t have to wait to contact a customer service representative.
  4. If the activation process is successful, close the office program and restart the computer.
  5. After the next launch, open Office again and go to File -> Account (or File -> Help in Office 2010 or older) and see if your Office installation appears as a licensed product or, for newer versions, as an activated product.

If you are not using a volume license key or have previously used a single purchased license, go to the following solution below.

Restoring a single purchased license

If you previously used a single purchased Office license that only allows installation on one computer at a time, and you did not remove the package before rebooting or selling the computer, the Microsoft activation server may generate an ERR_MISSING_PARTNUMBER error because it thinks you are actually trying to install the Office package more than once.

  1. If this scenario applies, you need to contact your Microsoft Live agent and ask them to activate your license key.
  2. To do this, simply open a ticket, describe your problem as best you can, and click the “Get Help” button.
  3. Then scroll through the list of self-help solutions and click on Sign In (under Get More Help).
  4. After logging into your Microsoft account, select the “Contact a current agent” option and follow the on-screen instructions to contact them.
  5. Note that after contacting the Microsoft agent, you will be asked for some security settings to confirm that you are the owner of the license key you are trying to activate. If everything is OK, the agent will activate your Office license remotely.

Frequently Asked Questions

Open the Office application and log in when prompted. If Office is still not activated, try running the online repair as described in the Repairing the Office application to restore the remaining Office installation. If you still can't activate, go to the next step.

If you're having trouble installing Office on your PC, try restarting your computer and then try installing Office again. If that doesn't work, use this simple recovery tool to completely uninstall Office. Once the uninstallation is complete, try reinstalling Office.

  1. Copy the code into a new text document. Create a new text document.
  2. Paste the code into the text file. Then save it as a batch file (named 1 click. cmd).
  3. Run the batch file as an administrator.

Click the File tab. Select the account. On the right side of the screen, you will see product activation information as shown below. If you see the words "Product Activated", then the activation was successful.