It will go live in the PlayStation Preview Program first before releasing in early 2019.
Following rumours about the same, Sony Interactive Entertainment announced that PlayStation Network users can soon finally, finally change their names. The Online ID Change function beta will be available in the PlayStation Preview Program by November end, allowing certain users to test out the feature, before it goes live for everyone in early 2019.
As with Xbox Live, changing your name the first time will be free, but will cost money afterwards. It’s $9.99 for regular PSN users, while PlayStation Plus members only have to pay $4.99. Though you can display your old name after the change, thus letting friends recognize you, take heed – this is something that can’t be reversed.
Sony also mentioned that the name change will work with all titles that have been published after April 1st 2018. This will, however, also include “a large majority of the most-played PS4 games that were released before this date.” Not every game and application for PS4, PS3 and PS Vita will be compatible though.
Some users may also “occasionally encounter issues or errors in certain games” following the name change. Changing back to one’s older name (which is free once the feature goes live) should fix this.