An Office product key uses a combination of 25 letters and numbers in this format:
Product keys include hyphens, but you can omit them when you enter your product key.
Use your Microsoft account, not your product key, to install and activate Office
Use your Microsoft account, not your product key, to install and activate Office and individually purchased Office apps, such as Project, Visio, Word, Excel, and Outlook.
Note: If you see the message "This product key has already been used" This means your product key has already been redeemed, and your Office product has been added to your Microsoft account. You don't need a product key to install or activate Office after it is added to your Microsoft account.
Sign in to install Office
Bookmark the site below so you always know where to go to install Office.
Sign in to activate Office
If an Office app prompts you to activate, sign in with your Microsoft account instead of a product key.
Use the right Microsoft account
Make sure you sign in with the Microsoft account that you used to buy Office.
There are a few exceptions where you'll need to do something other than sign in.
If you bought Office through your employer's Microsoft HUP benefit, you'll need your product key to activate Office on a PC. To get your product key, see Get your Microsoft HUP product key.
If you're using a volume license version of Office Professional Plus at work, you'll need to contact your admin for a product key.
If you see a yellow or red banner in an Office app that says SUBSCRIPTION EXPIRED, you must renew your Office 365 subscription to keep using Office. For help, see Renew Office 365 for home.
If Office came pre-installed on your new Windows 10 device, and you see a yellow or red banner in an Office app that says PRODUCT NOTICE: Office hasn't been activated, you must start a new Office 365 Home trial or buy Office. For help, see Activate Office.
I can't find my product key
Here's where to get help with your product key:
Is that an O or a 0?
Some numbers and letters look similar for Office 2007 and Office 2010 product keys. Use this guide to help tell the letters and numbers apart.
Contact support about my product key
If you’ve followed the guidance in this article and still need help, visit our Microsoft support page for assistance.