The Username for incoming Skype calls does not display on telephone handset.
Possible Solution:
Make sure that your telephone has support for Caller ID name and number display.
Possible Solution:
Some phones display numbers only and some phones will only display the name
if it is stored in the telephone’s address book. In this case, store the
Skype username and speed dial number in the address book in order for the Skype
username to display.