Microsoft's prices for added storage are higher than its main rivals in the consumer market, Apple and Google. Some Computerworld staffers based in the U.S. Personal Vault has debuted in some markets, and should be available globally by year's end, according to Microsoft.

Personal Vault, Microsoft said, would be accessible only through a second step of identity verification, such as a fingerprint, face scan or one-time codes texted to the user's smartphone. Around the same time, Microsoft also touted something it called OneDrive Personal Vault, a protected partition for storing the most sensitive and important files. In June, Microsoft announced plans to provide supplementary storage to Office 365 Personal and Office 365 Home subscribers but did not tip to a timetable. 'For Home subscriptions, only the primary subscription holder may purchase additional storage, and only for that user's account,' the tiny type read.

In fine print at the bottom of the plans' presentation page, Microsoft said that the additional space would not be accessible to every user on an Office 365 Home plan.

Microsoft cloud storage cost