Creating your Cities XL™ account During installation, you will be asked to register your copy of Cities XL™ in order to play the game. You must create an account on citiesxl.com and enter the serial number found on back of the manual. To do this, go to the following address: citiesxl.com/signup
Enter the information requested to create your account. Make a careful note of your username and password; you will need them to play the game.
Then start up the game. On first login the game will automatically find and download all new patches.