For those gamers whose parents got them PlayStation Network sub accounts in order to control spending on games and other content and are now age 18 or older, Sony brings great news to that group of young adults.
Eric Lempel, VP of Sony Network Entertainment, announced on PlayStation.Blog a feature lots of gamers have asked for: upgrading from a sub account to a master account. The trophies, friends’ list and request and many other features will now be available to users who make the switch to master accounts. To start the process, users will have to log in to the Sony Entertainment Network web site [https://account.sonyentertainmentnetwork.com/].
For more info, check out the Sub Account Graduation to Master Account page, and click on “Where/How to upgrade” and then on “Show images.”
[Source]: PlayStation.Blog: PSN: Upgrade Sub Accounts to Master Accounts.