The Workbook key is a unique ID key identifying your computer (also called a “Domain”). The number of domains that can be associated with a license key depends on the version of your spreadsheet:
- The Advanced Version allows a license key to be used by 1 user on up to 2 domains (i.e. 2 personal computers such as a laptop and a desktop)
- The Pro Version allows a license key to be used by up to 5 users on up to 10 domains (i.e. 10 computers within the same office)
Once the maximum number of domains has been reached for a particular license, the spreadsheet will not work on any other computers. You can easily manage / delete domains associated with your license key by accessing your account page (see “How can I associate my license with another computer?” for more details).