PlayStation Network sub account holders who are at least 18 can now upgrade to master accounts, according to a PlayStation Blog post by Sony Network Entertainment VP Eric Lempel.
"Starting today, PlayStation Network (PSN) users will gain the ability to upgrade a sub account to a master account," Lempel wrote. "We’re always listening to user feedback, and this is a feature that many of you have asked for. You’ll be able to upgrade an account first through the web and later through PlayStation 4."
A PlayStation Knowledge Center article explains the limitations of the system prior to today's changes, saying that sub account could not be changed even if the account holder turned 18.
You can find the steps necessary for the upgrade in a new PlayStation Knowledge Center Article. PlayStation 3, PlayStation 4 and PlayStation Vita owners are eligible and will keep their online ID, trophies, friends list, games, videos, music and other services. Both the master account holder and the sub account holder will be notified of the change.
An EU PlayStation forum post from online support coordinator SuperFastZombie also explains the ramifications.
"Upgrading to a master account will allow you access to the full range of online and account features without losing access to your Friends List, Trophies and any Store content purchased on the sub account (even if funded by the master account)," SuperFastZombie wrote.
Sony Network Entertainment sub accounts are designed for players under 18. They are beholden to and must be created in association with master accounts. A parent or guardian holding a master account can monitor the activities in sub accounts, whose holders are limited in several ways covering features like spending limits and gameplay broadcasting restrictions.