. While you may find websites claiming to offer "UPD Free" (updated free) activation keys, these are typically unauthorized and pose significant security risks. Activation Methods for Office 2013 (v15)
To fully use Office 2013, it must be activated. Without activation, the software enters "reduced-functionality mode," which only allows you to view documents without editing or saving them. Microsoft Support --- Microsoft Office 15 Product Key Activation UPD Free
"Office 15" was the internal codename for Microsoft Office 2013 it must be activated. Without activation
How to find product key for Microsoft Office already installed the software enters "reduced-functionality mode