Dropbox currently hosts over 35 billion Office files and 1.2 billion people use Office.
The deal means that you will be able to access Dropbox from Office applications, edit Office files directly from Dropbox and synchronise them across different kinds of devices. You will also be able to share new or edited files from Office apps using the Dropbox sharing features.
Microsoft said it will include the features in its next updates to Apple iOS and Google Android operating systems. These are due in a couple of weeks.
Web integration won’t be available until the first half of next year and Dropbox will make its applications available for Windows Phone and Windows tablet devices.
Dropbox for Business customers need an Office 365 subscription to use the features.
Satya Nadella, the CEO of Microsoft, said both companies will provide their shared customers with tools to create, share and collaborate across most nearly all devices.