An Office product key uses a combination of 25 letters and numbers, and looks like this: XXXXX-XXXXX-XXXXX-XXXXX-XXXXX.
• Downloaded Office from an online store – check your email receipt from the store (it may be in your Junk folder).
• Bought a physical box or card – look on the card or packaging.
• Office came with your computer – look on the Certificate of Authenticity.