Found this..Alittle outdated maybe but I bet there are similar rules for 2013. Our company still sends out 2003 with new computers. I bet we don't qualify for this..
Home Use Program
What products can I get through HUP?
The list of products varies by region, offering, application, version, and language. HUP typically offers your qualifying employees Microsoft’s most popular and newest Office System products, for a fraction of what they would pay to own the products outright. As an example, your qualifying employees who use Office Professional Plus 2010 on their work computers at your company would be eligible to acquire the HUP equivalent (Office Professional Plus 2010 HUP or Office 2011 for Mac) for use on their home (or mobile) computers.
To address the needs of multilingual individuals who routinely create or edit documents and presentations in different languages, HUP offers you optional Office Language Packs that enable Document Proofing Tools, Localized User Interface, and Help and User Assistance Tools for 37 different languages.