Office for mac activation

When you activate office 2011, the product key information is sent to Microsoft together with a hardware hash. The hardware hash is a non-unique number that is generated by using the computer's hardware configuration. The hardware hash does not represent any personal information or information about the product. The hardware hash cannot be used to determine the make or the model of the computer. Additionally, the hardware hash cannot be backward-calculated to determine the raw computer information. In addition to standard computer information, some additional language settings are collected. This information is not used to identify you. The information is used only to confirm that you have a licensed copy of the product, and to aggregate the information for statistical analysis.

The above paragraph is from a Microsoft FAQ on activation.

The licence that I have allows you to install Office on a desktop Mac and a Portable Mac, providing that you own and control both machines. You would need to look at the terms of your own software licence as their are differences depending on which version you have purchased.

You can reinstall Office as many times as you like on the same machine. Microsoft also allows a limited number of activations on new machines, as it understands that people do upgrade their hardware. Microsoft does not publish exactly how they track this, but most companies look at how often and the length of time between activations, before it blocks the serial key from being installed on a new machine. At this point you would need to contact Microsoft.