Create EA / Origin Account for son

I have just recently created an EA / Origin account for myself.

My 9 year old son would like to play NFS Most Wanted online / multiplayer on XBox 360 and to access all the games functions. 

When the game first loads it will not allow him to create an account because of his age presumably?

Surely there must be a way to allow him to enjoy the full benefits of this game?

Any help would be appreciated.