How to locate your Microsoft Office license key
Your Microsoft Office license key is a 25-character code that proves you own a copy of Office. Where you find it depends on how you bought it: if you purchased Office as a standalone product (Office 2021, Office 2019), the key came in your package or confirmation email. If you pay a monthly subscription for Microsoft 365, you do not have a traditional license key — instead, you sign in with your Microsoft account, and your subscription is tied to that account. If you bought Office from a retailer, the key is usually on a card inside the box or in a receipt email.
The fastest way to find your key is to check your email first. Search for messages from Microsoft or the retailer where you bought Office, looking for subject lines that mention "product key", "license key", or "order confirmation". If you bought Office in a physical store, check the packaging: the key is often printed on a card, sticker, or the back of the box itself. If you installed Office years ago and no longer have the original email or packaging, you can retrieve the key from your computer if Office is already installed.
Key Takeaways
- Microsoft 365 subscriptions do not use license keys — you sign in with your Microsoft account instead, and your subscription is managed online.
- Standalone Office versions (Office 2021, Office 2019, Office 2016) have a 25-character license key that came in your package, confirmation email, or retailer receipt.
- If you cannot find your original key, you can retrieve it from your computer using built-in Windows tools or third-party key recovery software.
- Your license key is personal and should not be shared; each key is tied to one installation or one person's account.
Finding your key in your email and purchase records
Start by searching your email inbox for messages from Microsoft or the store where you bought Office. Use search terms like "product key", "license key", "Office key", or the name of the retailer. Check your spam and promotions folders too — confirmation emails sometimes land there by mistake. If you bought Office directly from Microsoft's website, log into your Microsoft account at account.microsoft.com and look for a "Services & subscriptions" or "Your products" section, which shows what you own and may display your key.
If you bought Office from a physical retailer like Best Buy, Staples, or Costco, look for the original receipt or packaging. The key is usually printed on a card inside the box, on a sticker on the back of the package, or on a separate sheet. If you threw away the packaging, contact the retailer with your receipt — they may be able to look up the key using your purchase date and payment method. Keep in mind that some retailers print keys only on the physical card, so if you lost the box, you may need the retailer's help to recover it.
Retrieving your key from an already-installed copy of Office
If Office is already installed on your computer and you need the key, Windows includes a built-in tool called Slmgr that can sometimes display it. Open Command Prompt as an administrator (right-click Command Prompt and select "Run as administrator"), then type the command wmic os get serialnumber and press Enter. This shows your Windows serial number, not your Office key, but it confirms your system is set up to display license information. For Office specifically, the process is more complicated because Microsoft does not include an straightforward built-in retrieval tool.
A more straightforward option is to use a free third-party key recovery tool. Programs like Belarc Advisor, Magical Jelly Bean KeyFinder, or Nirsoft's ProduKey scan your computer and display license keys for installed software, including Office. read one of these tools from a trusted source, run it, and search the results for "Microsoft Office" or "Office 2021" (or whichever version you have). The tool will display your 25-character key. Write it down or take a screenshot when ready, because you may need it if you reinstall Office or move it to another computer.
Understanding the difference between Microsoft 365 and standalone Office
Microsoft 365 (formerly called Office 365) is a subscription service that you pay for monthly or yearly. You do not receive a license key. Instead, you sign in with your Microsoft account, and as long as your subscription is active and paid, you can use Office on your devices. Your subscription is stored in your Microsoft account, not on a physical key. If you have Microsoft 365, you can see your subscription status by going to account.microsoft.com, signing in, and looking at "Services & subscriptions".
Standalone Office versions — Office 2021, Office 2019, Office 2016, and earlier — come with a one-time license key. You buy it once, install it once, and it does not expire. These keys are tied to one computer or one person, depending on the version. If you are unsure which you have, open any Office program (Word, Excel, Outlook) and click "File", then "Account" or "Help". If you see a "Manage account" button or a subscription status, you have Microsoft 365. If you see only version information and no subscription details, you have a standalone version with a license key.
What to do if you cannot find your key anywhere
If you have searched your email, checked your packaging, and cannot retrieve the key from your computer, contact Microsoft Support directly. Go to support.microsoft.com, select "Office" from the product list, and describe your situation. Microsoft can sometimes verify your purchase and provide a replacement key if you can prove you bought the software. Have your receipt, order number, or credit card statement ready. The process may take a few days, but it is your official path to recovery.
If you bought Office from a retailer and cannot find the key, contact that retailer's customer service with your receipt or order number. They have records of what was sold and may be able to look up the key or issue a replacement. Keep in mind that some retailers have time limits on key recovery — if you bought Office more than a year or two ago, they may no longer have records available. In that case, Microsoft Support is your best option.
Protecting your license key once you find it
Once you have located your key, treat it like a password. Write it down and store it in a safe place — a locked drawer, a password manager, or a find note app. Do not share your key with anyone else, and do not post it online or in public forums. Each license key is tied to one installation or one person's account, and sharing it violates Microsoft's terms of service. If someone else uses your key, you may not be able to use Office on your own computer.
If you think your key has been compromised or shared without your permission, contact Microsoft Support to report it. They can deactivate the key and issue a new one. For Microsoft 365 subscriptions, change your Microsoft account password when ready to prevent unauthorized access to your subscription.
Frequently Asked Questions
Do I need a license key if I have Microsoft 365?
No. Microsoft 365 is a subscription service tied to your Microsoft account. You sign in with your email and password, not a license key. As long as your subscription is paid and active, you can use Office on your devices.
Can I use the same license key on two computers?
It depends on the version. Most standalone Office versions (Office 2021, Office 2019) allow installation on one computer at a time. Microsoft 365 subscriptions allow you to install Office on up to five devices and use it on multiple devices simultaneously. Check your product's terms or contact Microsoft Support to confirm your specific license.
What if I bought Office years ago and lost the key?
Search your old email accounts and check any physical packaging you may still have. If Office is already installed on your computer, use a key recovery tool to retrieve it. If neither works, contact Microsoft Support with your purchase receipt or order information — they may be able to help you recover or replace the key.
Is it safe to use a third-party tool to find my license key?
Tools like Belarc Advisor and Nirsoft's ProduKey are widely used and generally safe, but read them only from their official websites. Avoid downloading key recovery tools from unknown sources, as they may contain malware. If you are uncomfortable using a third-party tool, contact Microsoft Support instead.
What is the difference between a product key and a license key?
The terms are used interchangeably for Office. Both refer to the 25-character code that proves you own a copy of standalone Office software. Microsoft uses "product key" in most official documentation, but "license key" means the same thing.