Windows 10 Mobile users who download and use the free Word, Excel and PowerPoint Office apps will have to pay for editing privileges if those apps are used in Continuum mode. The company says that will go into effect starting on April 1, 2016.
In a post on Microsoft's official Office blog, the company stated:
"Editing in Word, Excel and PowerPoint with Continuum for phones will require an Office 365 subscription, but is available to try without Office 365 through March 31, 2016."
In other words, if you own a Lumia 950 or Lumia 950 XL and connect the optional Display Dock to use the phone like a PC on a big screen monitor, you won't be able to edit documents on Word, Excel or PowerPoint without a paid Office 365 subscription starting on April 1. While this may seem odd, it is also reflective of Microsoft's current policy that editing on Office apps with screens larger than 8 inches will need a paid Office 365 subscription.