You need to enter and update your Yahoo! Address Book contacts in a browser after you sign in to your Yahoo! account. In particular, you might want to update contacts' phone numbers and addresses with exact information—for example, area codes and house numbers—which will enable the optimum use of Address Book's calling and driving directions functions.

After you make a change in your Yahoo! Address Book, you might want to synchronise Address Book in Yahoo! Go 2.0 with the same changes. In some devices such as a Blackberry, you can use the option Address book sync. To synchronise Address Book in less powerful devices, it is necessary to delete the application, download it, and start it again.