Microsoft is targeting the growing mobile workforce with a 15 percent hike in license fees directed primarily at companies that have employees who use smartphones and other mobile devices in their work.

According to Mary Jo Foley, the new licensing agreement goes into effect December 1 for customers with the user option for its “client access licenses” (CAL). The User CAL is meant for companies that have employees who use iPhones, iPads, tablets and other devices. As more people bring their own devices to work, the User CAL has become increasingly popular. The other option is a Device CAL, which allows multiple people to access one device such as a PC at a nurse’s station.

Until now, the licensing costs have been the same for User and Device CALs. As of December 1, the following products will be affected by the licensing fee increase to the User CAL:

• Bing…