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.
You can sign in to activate Office 365, Office 2016, or Office 2013
If you subscribe to Office 365 and Office is prompting you for a product key, you can enter your Microsoft account instead. Try selecting the Sign in with an active account instead link in the Enter your product key dialog box and sign in with the Microsoft account that you associated with Office. We can help if you can't remember the Microsoft account you use with Office.
There are a few exceptions where you'll need to do something other than sign in.
If you bought a DVD or USB drive through your employer's Home Use Program (HUP), you'll need your product key to install Office on a PC. To locate your product key online, see Find your 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 Try, buy, or activate Office that's pre-installed on a new PC.
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.