Right here on one page we have consolidated a number of sources of information for Visual Studio Licensing: Help.
Licensing Explained – Learn how and why to license Microsoft software.
Licensing Instructions – Step by step instructions for registering licenses.
How to… Videos – Video tutorials and useful links.
Useful Contact Information – Useful telephone numbers for Microsoft support.
Visual Studio Blog – Our collection of useful Visual Studio developer information.
Volume licensing: Step-up Licenses enable organizations to upgrade their existing MSDN subscriptions for the remainder of the agreement term. Step-up Licenses are available in the Enterprise Agreement, Select, Select Plus, and Open Value programs in Microsoft Volume Licensing.
The cost of a Step-up License depends on when it is acquired. So, a Step-up License that is acquired during the second year of a three-year agreement will cost more than a Step-up License that is acquired during the third year of the agreement.
A Step-up License can be acquired at any time; however, the price is the same for any point in time within a given year of an agreement. For example, a Step-up License that is acquired four months into the second year of a three-year agreement will cost the same as a Step-up License that is acquired at the beginning of the agreement’s second year. This is a function of how Microsoft Volume Licensing works rather than anything specific to MSDN subscriptions.
Note: Customers whose program does not offer Step-Up Licenses can still take advantage of Step-Up Licenses by renewing within Open Value and immediately buying Step-Up Licenses.